The following is an excerpt about the discovery and mining of corundum in N.C. taken from pages 43-48 of Gems and Precious Stones of North America by George Frederick Kunz, from 1890. Forgive any typos on my part, sorry!
Rev. C.D. Smith, of Franklin, N.C., who had served as as an assistant to Professor Emmons on the State Geological Survey, discovered most of the important localities in North Carolina. In 1865 a specimen was brought to him from a point west of the Blue Ridge which he recognized as corundum; he visited the locality, found the mineral, collected specimens, and announced the occurrence. This was the origin of the mining industry now so valuable. These discoveries led to further exploration, and many localities were found in the same region which have since been more or less developed. The principal deposits that are now worked are the Jenks, Lucas, or Culsagee Mine; Corundum Hill Mine, near Franklin, Macon County, N.C.; the Buck Creek or Cullakenee Mine in Clay County, also at Laurel Creek in Rabun County, Ga., and near Gainesville, Hall County, Ga. The Jenks Mine is on the Culsagee or Sugartown fork of the Tennessee River. Its two names are derived from the locality and from the name of its first operator, Charles W. Jenks, of Boston, Mass. Prof. Washington C. Kerr, State Geologist of North Carolina, placed the mica-bearing rocks in the upper part of the Laurentian series, identifying them provisionally with those called by Dr. T. Sterry Hunt, Montalban. Thomas M. Chatard, of the United States Geological Survey, has described quite fully the occurrence of corundum at the Culsagee and Laurel Creek localities, both of which are now operated by the Hampden Emery Company, of Chester, Mass. The Culsagee outcrop, covering some thirty acres, consists of chrysolite (dunite) mingled with hornblende. The corundum is enclosed among various hydromicaceous minerals, commonly grouped, under the term chlorite, between the gneiss and the dunite, from the alteration of which they have evidently been formed. It occurs chiefly in crystalline masses, often of considerable size, and sometimes suitable for gems. At other parts of the mine it is found in small crystals and grains mingled with scales of chlorite, forming what is called the "sand vein." This is so loose and incoherent that it is worked by the hydraulic process; and the small size of such corundum is the saving of much labor in the next process of pulverizing. The Laurel Creek Mine is similar in character. At Buck Creek the chrysolite rocks cover an area of over 300 acres, and from that point southward the hornblende rocks assume greater proportions, being associated with albite instead of the ordinary feldspar and forming an albitic cyanite rock. There is also found here the beautiful green smaragdite, called by Professor Shepard chrome arfvedsonite, which, with red or pink corundum, forms a beautiful and peculiar rock curiously resembling the eclogite or omphacite of Hoff, in Bavaria, Germany. At Shorting Creek in Clay County and in Towns County, Ga., there are also corundum localities. The resemblance in the occurrence of the North Carolina corundums to that of Mramorsk in the Ural Mountains, as described by Prof. Gustav Rose of the University of Berlin, has been shown by Professor Genth. There the associated species are serpentine and chlorite schist, sometimes with emery, diaspore, and zoisite, very similar to the chrome serpentine corundum belt of the Southern States. The emery deposits of Asia Minor and the Grecian Archipelago, according to Dr. J. Lawrence Smith, yield that substance in marble or limestone, overlying gneissic rocks; while with it are associated many of the same hydromicaceious and chloritic speciesthat accompany both the New England emery and the Southern Corundum.
With more particular reference now to the actual gems yielded at these various localities, we may note that they occur in two distinct forms: first, as crystals, of which the usual forms for sapphire are double terminated hexagonal pyramids, often barrel-shaped by the occurrence of a number of pyramidal planes of successively greater angle; and second, as nodules of purer and clearer material, in the midst of larger masses of ordinary cleavable corundum. The latter, when broken or falling out, are sometimes taken for rolled pebbles, which they resemble.
In 1886, a London periodical made the statement that any one who found the sapphire or the ruby in its original matrix would be alled the "King of Rubies," and that his fortune would be assured. This recalls the fact that Charles W. Jenks, of Boston, was the original finder of the true corundum or sapphire gems in place in the Jenks Mine at Franklin, N.C., and that he obtained from this locality nearly all the fine crystals of the best American collections. One of the most interesting of these is a piece of blue crystal with a white band running across it and a place in the center where a nodule had dropped out. This piece was cut and put back in its place, and the white band can be seen running across both gem and rock. (See Colored Plate No. 1). Nearly all the fine gems from Franklin, N.C., were brought to light by Mr. Jenks' mining; but although found here in their original matrix, they were of such rare occurrence that it was found unprofitable to mine for them alone. The work was suspended for some time in consequence of the financial crisis of 1873, but has lately been resumed by the Hampden Emery Company, as mentioned, who now own the mines, and are operating them for corundum under the direction of Dr. S.F. Lucas, whose name has been given to the mine at Culsagee, formerly called after Mr. Jenks. What success in gem-discovery is at present attained, it is not easy to learn. Certainly but few gems have appeared in the market of late from that locality.
The largest crystal ever found, which is five times larger than any other known crystal, is one early discovered by Mr. Jenks and described by Professor Shepard. It is now in the cabinet at Amherst College; but much injured by the disastrous fire of 1882, which destroyed so many fine specimens of the Shepard Collection there. This crystal weighs 312 pounds, is perfectly terminated, partly red and partly blue in color, but opaque. (See Illustration). Another large crystal, also obtained by Mr. Jenks and purchased by Professor Shepard, weighed 11 3/4 pounds. These two specimens are more fully described as follows: The largest is red at the surface, but of a bluish-gray color within. The general figure is pyramidal, showing, however, more than a single six-sided pyramid, whose summit is terminated by a rather uneven and somewhat undefined hexagonal plane. The smaller crystal is a regular hexagonal prism, well terminated at one of its extremities, the other being drusy and incomplete. The general color is a grayish-blue, though there are spots, particularly near the angles, of a pale sapphire tint. Its greatest breadth is 6 inches and its length over 5. Some of the lateral planes are coated in patches with a white, pearly margarite. Only the smaller crystals found at Franklin furnish material suitable for use in jewelry. They are frequently transparent near their extremities, so that small gems can be cut from them; but scarely any of those thus far obtained are worth $100 and not 100 have been found in all.
In variety of color the North Carolina corundum excels; it is gray, green, rose, ruby-red, emerald-green, sapphire-blue, dark-blue, violet, brown, yellow of all intervening shades and colorless. Many specimens have been cut and mounted, especially of the blue and red shades, and make good gems, though not of the choicest quality. The two finest rubies are in the collection of Clarence S. Bement, of Philadelphia, in a suite of the choicest crystals found at the Culsagee Mine. Among these is probably the finest known specimen of emerald-green sapphire (oriental emerald). It is the transparent part of a crystal of corundum, 4X2X1 1/4 inches, from which could be cut several pieces that would together furnish from 80 to 100 carats of very fine, almost emerald-green gems (not too dark, as in the Siamese), the largest possibly 20 carats or more in weight. As its color is one of the rarest known, it makes this specimen a very valuable one. There is in this collection a beautiful crystal of yellow and blue in consecutive bands (see Colored Plate No. 1) from which it is estimated that at least $1000 worth of gems could be cut. A dark-blue stone of 1 carat weight is in the United States National Museum at Washington, and a series of fine red and blue crystals have been deposited there by S.F. Lucas. In the collection disposed of by Prof. Joseph Leidy, of Philadelphia, a few years ago, were several gems from the same mine, including a wine-yellow sapphire of 3 1/4 carats (660 milligrams); a violet-blue stone of a little over 1 carat (215 milligrams); and three dark-blue ones weighing respectively about 1 1/2 (320 milligrams), 1 1/4 (250 milligrams), and 3/4 (145 milligrams) carats each. In Professor Genth's suite of corundums are some from North Carolina and Pennsylvania that would afford opalescent stones with fixed stars and other interesting forms. Many fine examples of corundum from Pennsylvania are in the cabinets of W.W. Jefferis, now of Philadelphia, Lewis W. Palmer, of Media, and Dr. Cardesa, of Claymont. Specimens from Pennsylvania and North Carolina are also to be found in the cabinets of Joseph Wilcox and Dr. Isaac Lea, and in the William S. Vaux caminet at the Philadelphia Academy of Natural Sciences. Near the Franklin, N.C., locality there has been obtained a considerable about of a brown variety of corundum, which shows distinct asterism, both by artificial light and in the sunlight, when the stone is cut en cabochon. A similar variety, though of darker brown, with a bronze-like reflection, has also been found, some twelve miles from Franklin, by Mr. Chatard. These all show a slight bronze play of light on the dome of the cabochon in ordinary light, and under artificial light they show well-defined stars, being really asterias or star-sapphires, and not cat's-eyes, as might seem at first sight to be the case. Similar light-brown corundums, showing asteriation and clevage faces of the crystals, are to be found in Delaware County, Pa. A fine opalescent variety of deep indigo color is reported by E.A. Hutchins, as obtained by him from near Franklin and elsewhere in Macon County. Red and pink corundum is found at the Cullakenee Mine, in Buck County, and also at Penland's, on Shooting Creek, in Clay County. From the former locality there is a fine ruby-colored specimen in the cabinet of the Philadelphia Academy of Natural Sciences, and in the Vaux Collection a remarkable black crystal, the locality given for which is Buncombe County.
Among other varieties found at various points in North Carolina , the following may be noted: Two miles northeast of Pigeon River, near the crossing of the Asheville road, in Haywood County, and two miles north of this, on the west fork of Pigeon River, at Presley Mine, are found some of the finest colored specimens of blue and grayish-blue corundum. Twenty miles north-east of this, at the Carter Mine, fine white and pink corundum occurs in crystals and in a laminated form. Blue, bluish-white and reddish corundum at Belt's Ridge and more recently some very fine, fair colors from several new localities near Statesville. Fine crystals have also been found in the Hogback Mine, in Jackson County.
The following two excerpts are from The Rubies of Cowee Valley by Lou Harshaw (New Revised Edition, 1978), pages 5-6 & 11-12. The first is from the section on the history of the Cowee Valley, and the second from the section on the history of Corundum Hill. As an aside, although the year 1893 is given here, Kunz, as shown by the excerpt above from 1890, looks to have reported on the N.C. rubies in this earlier work.
There are only two places in the world where sandy gravel yields up premier blood red rubies of the finest gemstone quality.
One is the renowned Mogok Valley in Burma.
The other, until recent years, was largely unknown except in commerical gemstone circles. The rubies of Cowee Valley in the western part of North Carolina are rapidly becoming as famous as the Burmese stones and have all the characteristics of those from the Burmese fields.
Dr. George Frederick Knuz of Tiffany's in New York, in "Mineral Resources of the U.S.," 1893, first officially reported on the North Carolina ruby fields. Tiffany & Company had received several choice stones for cutting, sent in by the local people, and were very interested in the location.
As more of the precious stones came to light, William E. Hidden (so prominent in the gem and mineral field that a rare discovery, Hiddenite, found in only one place in the world, was named for him) was a frequent visitor to the area and wrote many articles about the Valley. Older members of many of the resident families remember his visits.
Dr. Joseph Hyde Pratt, state geologist in the early 1900's, a man well respected as being the best authority and perhaps the most conservative voice on the Cowee rubies, in his "Corundum and Peridotites of Western North Carolina," had this to say:
"Some larger gems -- three or four carats in weight -- have been cut which were free from inclusions, and of fine color and transparency. A great number of smaller, perfect gems have been cut. In color and brilliancy, these are equal to the Burmese, and if the percentage of the unflawed, transparent material increases but little, this new field would be a well matched rival to the Burma fields."
The Caler Fork placer gravels of Cowee Creek had attracted attention in the very early years and in 1895, the American Prospecting and Mining Company began with heavy hydraulic equipment to wash the fields. They continued until 1899, when the yield proved too sparce.
The early professional prospectors soon realized that the original source of the Cowee Valley rubies was yet to be discovered. This is still true. Even today, perhaps there lies under age-old sand and gravel, a true ruby matrix.
The United States Mining Company, tracing the trail to a possible matrix, sank a shaft on a rise so likely, that it was already called "In Situ Hill."
Another company, also tracing the elusive original source, sank another expensive shaft at another location with tunnels and core drilling. All to no avail.
Corundum crystals were located in the hill, but their color was translucent pink and lilac, with no stones of the true ruby color such as occur in the Valley placers.
In 1907, work was suspended, but was resumed in 1913 when the Consolidated Ruby Co. of New York sank extensive drifts and conducted considerable core drilling. This work continued until 1914, when it became apparent that the work produced corundum of small size and poor color. It was obvious again that the matrix of the true rubies of Cowee had not been found.
For a time, almost 35 years, the rubies of Cowee went unnoticed and were not actively sought except for an occasional amateur geologist.
Will Holbrook, a native of the Valley, was one of the original owners of a mine site. Holbrook was known as the "man of rubies" in the Valley and was never without time to talk about rubies and show his finest stones which he carried with him in a cloth sack in his pocket. Largely, during the years of the commercial mining hiatus, the residents turned back to farming the land, Will Holbrook among them. But when the crops were in and the chores finished, he could be found down at the creek bend, looking for the pretty stones.
There was, however, still some interest on a national scale and one present day owner tells about his father. Members of a prominent gem company surveyed his land and wanted permission to sink a dozen or more shafts over it.
"No!" said the old timer, "Can't you see that my tomatoes, beans and corn are all growing there?"
The history of the Corundum Hill mining operations is both unique and fascinating. It closely parallels that of Cowee Valley and for that reason is included in this book. The serious collector, will, perhaps, find it more interesting than the casual visitor to Cowee.
Shortly after the Civil War, North Carolina turned its attention to the development of its natural resources including the mining of gems and minerals. Several prominent North Carolinians were largely responsible for the great interest in mining during this early peroid of the state's history-among them were General Thomas L. Clingman, who later served as United States Senator, State Geologist, Professor Washington C. Kerr, Mr. J. Adlai D. Stephenson, a mineral collector from Statesville, N.C., and professor C.D. Smith of Franklin, N.C. who was, at one time, assistant on the North Carolina Geological Survey.
At about this same time, on the farm of Hiram Crisp, situated on a hill seven miles southeast of Franklin, on Cullasaja River in Macon County, specimens of corundum were being plowed up in the fields.
Uncle Hiram, as he was known in the county, was curious about the rocks found on his place and knowing of Professor C.D. Smith of Franklin, went to him with the rocks. After careful examination of the stones, Hiram was informed that his find was corundum, that it had commercial value as an abrasive, and that it had, sometimes, a far greater value as a gemstone. The year was 1870.
News of this important find reached Col. Charles W. Jenks of Boston, Massachusetts, and in early 1871, Col. Jenks purchased or leased the land and the Cullasaja mine (later to be known as Corundum Hill) was opened. In addition to being the first attempt toward a systematic mining for gems in North Carolina, the Cullasaja mine was the first mining operation in which gem sapphire was found in its original source or matrix. Many fine gems were obtained from the Corundum Hill shafts. However, the number found did not warrant mining solely for the gems and so, after a few years, the mine was operated for corundum to be used for abrasive purposes. The financial crises of 1873 forced the shut down of the Jenks operations on Corundum hill.
The mine was subsequently purchased by the Hampden Emery Co. of Chester, Massachusetts and operated under the direction of Dr. S.F. Lucas. Several other companies have operated on Corundum Hill, but with the development of man made Carborundum, all natural abrasive mining operations within the state were ceased, thus closing the era of corundum mining in North Carolina.
During its commercial mining operations and since, Corundum Hill has produced thousands of fine gems and cabinet specimens. They range in color from the red of the ruby through every shade of the rainbow. Hundreds fill the collections of prominent museums in the United States and foreign countries. The largest crystal on record weighed 312 pounds, was 22 inches long, 18 inches wide and 12 inches thick. This large crystal is red on the surface, graduating to a blue gray in the center. The oriental emerald, a name given to the emerald green sapphire, is a very rare color in corundum. An exceptionally large oriental emerald was found in early mining operations. The partly transparent crystal is four inches long, two inches wide and one and a half inches thick. It has been said that 80 to 100 carats could be cut from the stone with the largest, perhaps 20 carats. Good specimens of green corundum are to be found along with the various shades of red, the yellows, blues, purple, and gray tones of the sapphires that go to make Corundum Hill a very popular place.
The next three excerpts are from (in order) Corundum and the Peridotites of Western North Carolina by Joseph Hyde Pratt and Joseph Volney Lewis (1905), pages 245-250; History of the gems found in North Carolina by George Frederick Kunz (1907), pages 17-22; and Corundum and its occurrence and distribution in the United States by Joseph Hyde Pratt (1906), pages 98-101. All of these books have been scanned into Google Books (where I found them) so if you want to read more or see the pictures referenced, they can be easily found.
It was in this county that corundum was first mined in North Carolina, and from 1893 to 1900 it was the only county producing any corundum for market.
In the valley of the Little Tennessee River above Franklin there are a great many peridotite outcrops, most of which are indicated on the map, Pl. II. Emery has been found at a number of these places, but corundum, as far as is known, at only one. This locality is at the head of Hickory Knoll Creek, at an elevation of about 4000 feet, on the western slope of Fish Hawk Mountain. A number of small dunite outcrops are found here, and where these are exposed near the surface, they have a well-developed radial enstatite casing (Pl. XIV, A). A small amount of corundum has been found associated with them.
Six miles southeast of this, and just south of Mount Scaly, corundum has been found in small crystals and grains, with outcrops of soapstone and a fibrous, asbestos-like mineral. Radiating cases of talc, enclosing an ocherous, earthy material, are found here, representing the original peridotite, which is not now visible on the surface.
Near Coweeta, pink corundum has been found embedded in masses of a greenish cyanite, but none has been found in place.
The most important corundum region in the mountain district lies 7 miles southeast of Franklin, just north of the cullasaja River, and between Ellijay and Walnut creeks, two of its tributaries. On this, one of the most prominent western spurs of the Cowee Mountains, are found more promising corundum localities than in any other region of equal area within the State, or indeed, in the whole Appalachian crystalline belt. In this region, within a total area of less than 20 square miles, there are at least fifteen distinct areas of peridotite; and corundum in greater or less quantity has been found associated with nearly all of them.
Corundum Hill mine. - On the southern point of this spur is the Corundum Hill mine, which is the most widely known mine in the country and the one that has furnished by far the greater part of American corundum since the beginning of the industry.
This mine is 7 miles southeast of Franklin, on Cullasaja Creek, a tributary of the Little Tennessee River. The post-office is Cullasaja. Since the beginning of active mining here in 1878, it afforded a constant annual product of 200 to 300 tons of cleaned corundum up to 1900; but since that time there has been but a small amount of corundum mined.
Work was begun here in 1871 by Col. C. W. Jenks, and there being then no precedent or guide in mining for corundum, many mistakes and failures were made during the first year. For instance, the value of sand corundum was not then realized, and the only material put on the market besides gems and cabinet specimens consisted of the larger crystals and pieces of massive corundum. About 100 tons of this material were mines, which as fully 90 per cent pure. This was sold to the S. S. White Dental Co. of Philadelphia, Pa., and to Pusey Jones & Co., of Wilmington, Del., and several small lots were sent abroad.
The Corundum found at this mine occurs in a peridotite rock and has been worked very extensively, especially near the contact of this rock with the gneiss. Plate XXV is a general view of this peridotite formation and shows to a certain extent the number of openings that have been made in mining for corundum. The summit of this hill is about 500 feet above the level of the Cullasaja Creek. Plate VI is a topographic and geologic map of this peridotite formation and shows the location of the various mines. It is a rather blunt, lens-shaped mass of dunite, covering an area of about 10 acres, over most of which the rock is exposed. As is seen from the map, most of the openings are located near the contact of the dunite with the gneiss or schist, along border veins of corundum. A number of interior veins have been worked within the formation but with the exception of the one marked "Shaft" on the map, they have all soon pinched out; and they can be profitable worked only in connection with the larger border veins.
Most of the mining has been done on the south side of the formation, where was encountered what is known as the "Big Vein." This was first mined by means of open cuts, and later by tunnels, the last one being about 300 feet below the summit of the hill. Plate XXVI is a view of the entrance to this tunnel, and shows the peridotite rock on the left and the gneiss beyond the cut on the right. For nearly the whole distance of the southern boundary of the dunite formation, a cut has been made, following the contour of the hill. This cut was sometimes wholly within the gneiss, at other times wholly within the peridotite, and again it was directly on the contact. The tunnels are all to the left of the cut, and they have encountered corundum almost continuously for a distance of 1280 feel, reaching almost to the southeast boundary of the formation. Plate XXVII is a view of the southeastern end of this cut, showing the peridotite on the left and gneiss and schist on the right. The upper part of this cut is known as the Stanfield mine. A tunnel has been run into the hill near the contact, and in place the vein of corundum was 8 to 10 feet wide. No work has been done at this point for a number of years.
On the northeast side of this formation is what is known as the Zeb Jones mine, in which there has been exposed a bench of ore 25 feet deep and 2 to 5 feet wide, uncovered for a distance of 50 feet, which averaged very close to 50 per cent corundum. This vein carries what is known as "buckwheat" corundum, which as its name suggests, is made up of small, irregular particles of corundum about the size of buckwheat grains (see B of Pl. XXI).
From the various openings, block, crystal, and sand corundum ores have been obtained, all of which can be readily cleaned and furnish a commercil product that can be used in the manufacture of any kind of corundum wheel. A small amount of garnet is occasionally found associated with the corundum in the vein near the southern contact, but this portion of the ore can readily be eliminated at the mine by hand cobbing.
The water supply at the mine is rather limited, but sufficient has been obtained to carry all the sand and gravel corundum to the mill in a line of sluice troughs a mile and a half in length. The rolling and scouring action to which the ore is subjected in going this distance does much toward separating the corundum from its accompanying impurities. The massive corundum is hauled to the mill in wagons, but as it is down grade practically all the way, to cost per ton of hauling is small. Cullasaja Creek furnishes all the necessary power for running the washing and cleaning machinery at the mill.
The Corundum Hill mine is owned by the International Emery and Corundum Company of New York, who also own the Buck Creek mine, in Clay County, N.C., and the Laurel Creek mine at Pine Mountain, Georgia.
At many of the other peridotite outcrops on the mountain between Ellijay and Walnut creeks, corundum has been found in greater or less quantity, and at two localities, the Mincey and Higdon mines, extensive mining was done several years ago.
The Mincey mine is located about 2 miles northeast of the Corundum Hill mine, 7 miles southeast of Franklin, and but a short distance above Ellijay Post-office. At this locality there is a considerable outcrop of peridotite (dunite), on a hill rising directly from Ellijay Creek. About 150 tons of corundum have been taken out of this mine by the Hampden Emery and Corundum Company which formerly owned the property. The main work consists of a large open cut in the midst of the formation, which was extended by means of a shaft and tunnel, the mouth of the tunnel being nearly on a level with the creek. Plate XXVIII is a view of this cut and shows its location entirely within the formation. Nearer the contact of the dunite with the gneiss another cut was made, in which some corundum was also found.
The amount of corundum mined and tht found on the surface and near the contact of the dunite with the gneiss indicate that it exists in quantity along the contact. The corundum that was mined here was hauled in wagons, after partial cleaning, to the mill at Cullasaja. A considerable portion of it was crystal corundum of a peculiar bronze color, known locally as "pearl corundum."
Near by is the Moses mine, which was also worked by the same company for a short time. Neither of these mines have been operated since 1894.
Between the Corundum Hill and Mincey mines there is a bold outcrop of dunite, covering about the same surface area as that at Corundum Hill. No mining has been undertaken here, but prospecting has been carried on to a limited extent by sinking numberous shallow pits at various points within the formation, at many of which corundum was encountered. Numerous boulders and gragments carrying corundum have been found near the lower borders of the formation and in the stream beds. Although no large deposit has as yet been located, there are strong indications of the existence of a corundum deposit of considerable extent at the contact of the peridotite with the gneiss. This property is owned by Mr. John Gray, of Ellijay, Macon County. Corundum has also been found on the land between the Gray property and Higdon mine, belonging to Mrs. J. L. Robinson, of Franklin.
Near the summit of the mountain on which the Corundum Hill mine is located, but on the opposite or Ellijay side, is the Higdon mine. This mine was opened in 1895 by Mr. Chas. C. Foster, of Boston, and is now owned by the American Corundum Company.
The outcrop of peridotites at this locality is not large and a small border vein of sand corundum was opened. The gneiss wall is generally very sharply defined, while on the opposite wall are the alteration products of dunite which pass into the normal rock. The vein was opened by a cut and shaft about 100 feet deep. A mill was built at the foot of the mountain on the Ellijay road and the corundum was carried to it in troughs by gravity. A considerable quantity of the ore was cleaned but none has been shipped. This property has not been worked since 1896.
Considerable work in the nature of prospecting has been done at the New Mincey and the Haskett mines, which are further up the creek, the latter being nearly at the summit of the Blue Ridge, about one-half mile from Cullowhee Gap. Neither of these properties has yet shown any quantity of corundum. Two miles above Mincey mine, and near the Cullowhee road, is the Jake Moore mine, where the little prospecting that has been done has shown the presence of what is apparently a border vein of the corundum.
Near the foot of the eastern slope of the Nantahala Mountains, on the Buck Creek-Franklin road, a small amount of corundum was found in a saprolitic rock. Mining on a small scale was undertaken here by Dr. H.S. Lucas, and a little of the ore was hauled to his mill at Franklin. There is no indication of any large supply of corundum here. Near Nona post-office, 7 miles west of Franklin, well-formed corundum crystals have been found in the soil resulting from the disintegration of gneissic rocks. At the Raby mine, on Burningtown creek, well crystallized corundum is sparingly found.
The Sheffield mine is in Cowee Township, about 7 miles a little northeast of Franklin, and about 1 1/2 miles nearly east of West Mills. It is on the north side of Cowee Creek, on a hill rising 150 feet above the creek, and was operated by the National Abrasive Manufacturing Company of New York. The corundum occurs in an amphibole-schist which is described on page 216.
The corundum is in oval-shaped nodules up to an inch in diameter, of a pink and purplish color; it is of exceptionally good quality and high abrasive efficiency. It does not constitute over 3 to 5 per cent of the rock, although in the seams or bands in which it is more or less concentrated (see fig. 26) the percentage is as high as 10. Associated with the corundum are a pink almandine garnet, which at times forms a considerable per cent, pyrrhotite and chalcopyrite in very small particles or seams, sparingly disseminated through the rock, and also very sparingly, small scales of graphite. On account of the depth to which decomposition has extended, the solid rock was observed only in the lower portion of the 87-foot shaft and nothing definite can be stated as to the extent of this corundum-bearing rock. Practically all the mining that has thus far been carried on here for corundum has been in the decomposed (saprolitic) rock, and this has been done by means of tunnels and shafts. The corundum could be profitably mined in this saprolitic rock, although it forms but 3 to 5 per cent of the rock, but when the hard, tough, undecomposed rock is encountered, which carries more or less garnet, the problem will be altogether different, and it is not probably that it can be economically mined.
A small cleaning plant has been erected at the foot of the hill near the creek, which has a capacity of about 2 tons a day.
Red, ruby, and gray corundum has been found in the gravel beds of many of the creeks flowing into the Cowee. Some massive pieces, 1 or 2 inches in diameter, of a ruby-red corundum have been found on the William West farm, near West Mills. A region that has attracted much attention is in the vally of Caler Fork of Cowee Creek, where is located the Ruby mine of the American Mining and Prospecting Company, described on page 181.
At the Read or Watauga mine, which is 6 1/2 miles east of Franklin, on the Dillsboro road, just above Watauga Creek, corundum has been found in a dike of saprolitic rock that probably was originally an amphibolite. The country rock is hornblende gneiss, but in the immediate vicinity of the dike no solid rock is encountered. The general occurrence is somewhat similar to that at the Isbel mine, in Clay County, and at the Acme mine, in Iredell County. The corundum is in prismatic crystal ranging in size from that of buckwheat grains to nearly 1/2 inch in diameter. They are of an almost uniform pale bluish color and some are semi-transparent to transparent. The ore was readily cleaned and furnished a nearly pure product. The mill at this mine has a capacity of two tons a day. As at all the localities where the corundum occurs in an amphibolite, its quantity is very limited.
In 1874, Mr. C.W. Jenks read a paper on the occurrence of sapphires and rubies in situ in corundum, at the Culsagee mine, before the Geological Society of London; in this brief but important article he described the location and mineralogical character of the mine, and the fact of the presence of portions in the corundum of true gem quality. The paper attracted much interest, and Prof. David Forbes said that great credit was due to Mr. Jenks, and that he had "discovered the actual home" of the true ruby and sapphire, which had never before been really traced to their sources (see Pl. I).
Some years later, a London periodical made the statement that any one who found the sapphire or the ruby in its original matrix would be called the "King of Rubies," and that his fortune would be assured. But such is not always the result to those who deserve it. Mr. Jenks was undoubtedly the original finder of the true corundum or sapphire gems in place, and he obtained from this locality nearly all the fine crystals of the best American collections. One of the most interesting of these is a piece of blue corundum with a white band running across it and a place in the center where a nodule had dropped out. This piece was cut and put back in its place, and the white band can be seen running across both gem and rock. (See colored Pl. 1) Nearly all the fine gems from Franklin, N.C., were brought to light by Mr. Jenks' mining; but although found in their original matrix, they were of such rare occurrence that it was found unprofitable to mine for them alone. The work was subsequently suspended for some time in consequence of the financial crisis of 1873, but resumed by the Hampden Emery Company.
The largest crystal ever found, which is 5 times larger than any other known, is one early discovered by Mr. Jenks and described by Professor Shepard. It is now in the cabinet at Amherst College; but much injured by the disastrous fire of 1882, which destroyed so many fine specimens of the Shepard collection. It weighed 312 pounds, and measured 22 inches in length, 18 inches in breadth, and 12 inches in thickness. In form it was a steep and somewhat irregular six-sided pyramid, terminated above by a rather uneven basal plane. Its general color is grayish blue.
In addition to these and other notable crystals, many public collections, besides the American Museum of Natural History (which possesses much the finest series), contain numerous cut gems from this mine.
A blue stone of over 1-carat weight is in the United States National Museum at Washington, and a series of fine red and blue crystals have been deposited there by S. F. Lucas. In the collection made by the late Prof. Joseph Leidy, of Philadelphia, and now also in the National Museum, are several gems from the same mine, including a wine-yellow sapphire of 3 1/4 carats (660 milligrams); a violet-blue stone of a little over 1 carat (215 milligrams); and three dark-blue ones weighing respectively about 1 1/2 (320 milligrams); 1 1/4 (250 milligrams); and 3/4 (145 milligrams) carats each.
In Dr. Spencer's notes on American gems in the British Museum of Natural History, London, is noted a specimen of corundum from Corundum Hill, Macon County, N.C., which consists of a rough hexagonal prism, 26 cm. long and 18 cm. across, of a reddish color.
In a recent report of Prof. J.H. Pratt, State Geologist, he thus refers to gems from this locality:
At the Corundum Hill Mines, Cullasagee, N.C., various shades of gem ruby corundum have been found. Two of the best rubies of good color that have ever been found at this mine are in the collection of Clarence S. Bement, of Philadelphia; there are also a number of fine ones in the United States National Museum at Washington. Many of the smaller crystals of various shades of pink to red are transparent near the outer surface and near their extremities, and from these small gems can be cut, but few that are worth more than $100 have been obtained from them.
Probably the finest emerald green colored sapphire in the world cam from the Culsagee mine sand is now in the Morgan-Bement collection at New York. This is the rarest of all the colors of sapphire or corundum gems, and is known as Oriental emerald. The specimen is a crystal 4 X 2 X 1 1/4 inches; part of it is transparent, and several very fine gems could be cut from it, see Plate XII.
Another locality in the same county, interesting, though less prominent, is the Mincey mine on Ellijay (properly Elegee) Creek, about 2 1/2 miles northeast of Corundum Hill. Some good ruby corundum occurs here, together with a peculiar brown or bronze variety, known locally as "pearl corundum," which shows distinct asterism, both by natural and artificial light, when the stone is cut en cabochon. In natural light these corundums all show a bronze luster and are somewhat similar to the cat's-eye, but in artificial light the star is more distinct. Most of the bronze corundum is in rough crystals, but some have been found that have the prismatic faces smooth and well developed, and these are often dark, almost black, in color. One crystal of this dark kind, found some years ago, yielded gems 2/3 of an inch in diameter. A similar asterism has been noticed in many of the rubies and sapphires from Cowee Valley, and at several other points in the State. According to Von Lasaulx, it is sometimes produced by rifts due to the basal parting. These rifts when examined with the microscope, are seen to be very thin, sharp, and rectilinear, and are parallel to the edge between the prism and the base. In other cases asterism is undoubtedly due to rutile or other minute crystals enclosed in the corundum, intersecting each other at an angle of 60, or in some similar systematic positions.
At the Cullakenee mine, Buck Creek, in Clay County, masses of emerald to grass-green amphibolite (also called smaragdite) are found, through which are disseminated particles of pink and ruby corundum, from the size of a pea to some as large as hickory nuts. The corundum is not of gem quality, but the combination of the green and pink makes very beautiful specimens, and as the rock is hard enough to take a good polish, it might furnish a decorative or ornamental stone of some value. It has been introduced for such purposes under the name of ruby matrix.
A similar association of green amphibolite with corundum, sometimes pink and sometimes dark blue, is found near Elf post-office, on Shooting Creek, in the same county. Other corundum localities in Clay County are the Foster mine, near the headwaters of the north fork of Shooting Creek, and the Herbert mine on Little Buck Creek.
Of late much attention has been aroused by the discovery of rich ruby corundum in small distinct crystals of a different character from any others found in the State, and in a different rock. These have been known as the Cowee rubies, from the locality in the Cowee valley, in Macon County. It has seemed as though here, at last, true gem rubies, equal to those of Burma, had really been found, and much interest has been felt in the discovery. Thus far, however, no very important results have been obtained, although some of the stones are unquestionably fine, but most of them are small (see Pl. I).
They are unusually interesting and beautiful as crystals, but many of them are imperfect. It is claimed, however, that the percentage of imperfect stones is no greater than it is in the rubies from Burma. Unfortunately, many of the crystals also have inclusions which mar their elegance as gems. The exact locality of this very interesting occurrence is a tract of some 10 square miles lying between Mason's Branch and the Caler Fork of Cowee Creek, affluents of the Little Tennessee River some 6 miles below Franklin, Macon County. Many interesting minerals are found in this area, and there are mica mines there, and mines where the abundant garnet has been worked for use as an abrasive. The beautiful rhodolite garnets, found in close association with the ruby crystals in the gravel and saprolite, will be described separately under garnet.
The discover and development of the "Cowee rubies" were first described in the volumes of the U. S. Geological Survey (Mineral Resources of the United States), in the writer's annual reports on the Production of Precious Stones, from 1893 to 1896, year by year, and further in that of 1899. Also in 1899, there appeared a full account by Prof. J. W. Judd, Mr. W. E. Hidden, and Dr. J. H. Pratt; and the latter gentleman has since published further accounts in his annual reports, and in his special bulletins on corundum in the United States.
The first published notice in the author's report for 1893, above mentioned, was of the finding of ruby corundum, in small hexagonal crystals, flat or tabular, in an alluvial deposit on the Reeves farm, not far from Franklin, associated with beautiful garnets. The next year's report described the locality as consisting of the valley of a stream, for several miles, in which the rubies were distributed through a gravel bed from 2 to 10 feet thick, overlain by several feet of surface deposit,- a mode of occurrence very similar to that in the Mogok Valley in Burma, where the finest rubies are obtained.
The attention of the author was first called to these rubies by the late Mr. James D. Yerrington, of New York, who had specimens, both cut and uncut, that he had received from Mr. Reeves, of Athens, Georgia, who owned the farm on which they had been found. Two cut gems of 1/2 a carat each, were set in a flag scarf-pin shown in the Tiffany jewelry exhibit at the Columbian Exposition of 1893; these were subsequently unmounted and displayed by the same firm at the Atlanta Exposition of 1895. They now form part of the Tiffany-Lea collection, included in that of the U. S. National Museum at Washington. A number of others (see figures), obtained at about the same time, are in the American Museum of Natural History, New York. A fine series, both of crystals and cut gems, was shown by the North Carolina Geological Survey at the recent Expositions at Buffalo, 1901, Charleston, 1901-02, and St. Louis, 1904.
In 1896, the locality was visited and examined by Mr. C. Barrington Brown, the eminent authority on ruby mining, who had previously prepared an exhaustive report on the Burma region, in conjunction with Prof. J. W. Judd, for the British Government.
In 1899, as above stated, Professor Judd and Mr. William E. Hidden published a joint article, with crystallographic notes by Dr. J. H. Pratt. This account embodied the results of Mr. Brown's visit, of Mr. Hidden's operations on the ground, and of Dr. Pratt's studies on the crystal forms and their relations. It had now become clear that the rubies from this locality occurred in a wholly different association from any other corundum in the State, and the title of the article was "On a New Mode of Occurrence of Ruby in North Carolina." The surrounding rocks are schists and gneisses, often containing corundum, but in enlongated crystals and not of gem quality. Only a few miles away are the dunite outcrops of the Culsagee and other localities, already described. But at Cowee the rock is wholly different, and the forms of the crystals also. The first accounts had reported a limestone as the probable source of the valley deposit, and even as the matrix of the crystals, as is the case in Burma. But further study had disproved this statement. Underneath the ruby-bearing gravel, comes a soft decayed rock to which the name of saprolite has been given,- a result of the decomposition of basic igneous rocks, in place. This is sometimes many feet in thickness, but gradually passes downward into the unaltered condition of the same rocks. Trial shafts show that this change begins from a depth of some 35 feet, when portions of the unaltered rock begin to be met with. The original rock, when reached, proves to consist of several related varities, comprising amphibolite, hornblende-eclogite (garnet-amphibolite of some authors), and a basic hornblende-gneiss, with some feldspars (labradorite and perhaps anorthite). Some of these rocks are doubtless the source of the rubies strewn through the saprolitic material and the overlying gravel, though their actual occurrence in the undecomposed rock has not yet been proved. The crystals are distinct from any others found in North Carolina, but resemble those in form those from Yogo Gulch, Montana (the sapphire variety) which are taken from true igneous dikes; and these flat and tabular hexagonal forms are regarded by students of crystallography as characteristic of corundum that has solidified from a molten igneous rock.
Another corundum occurrence in saprolitic rock, but the crystals blue and more prismatic, is noted by by Dr. Pratt at the Reed, or Watauga mine, 6 miles east of Franklin; and red, sometimes ruby, corundum is found in old stream gravels near West Mills; both of these are in Macon County. A number of minor occurrences are known throughout the general region, where there are small saprolitic areas.
There are many other localities of corundum in this group of counties, some of the more important or promising of which may be simply mentioned here. In Macon County, besides the important occurrences already described, corundum appears at Glenville, in chlorite schist; at Nona, on Thumping Creek, in nodules and flat crystals in gneiss; on Hickory Knoll Creek at an elevation of 4,000 feet on Fishhawk Mountain, in dunite; and at the Coweeta mine, of pink color in greenish cyanite. Of late, the emery variety has been found, and to some extent worked, at several points near Fairview Knob, in a basic magnesian rock, the principal mine being the Fairview, near North Skeener Gap, and the Waldrop mine on Dobson Mountain.
At the Corundum Hill mine, Cullasagee, N.C. (see description, p. 117), various shades of ruby-gem corundum have been found. Two of the best rubies of good color that have ever been found at this mine are in Clarence S. Bement's collection. There are also a number of fine ones in the United States National Museum at Washington. Many of the smaller crystals of various shades of pink to red are transparent near the outer surface and near their extremities, and from these small gems can be cut; but few that are worth $100 have been obtained from them. These smaller crystals are usually well developed and have a clean-cut form. The faces commonly developed on these are the base c (0001); the unit prism, m (1010); the unit rhombohedron, r (1011), and the pyramid, n (2243), more rarely observed.
The North Carolina locality for corundum gems which has attracted the most attention is the tract of land between the Caler Fork of Cowee Creek and Mason Branch, tributaries of the Little Tennessee River. This tract is situated in Macon County, almost 6 miles north of the town of Franklin. The nearest railroad station is Dillsboro, Jackson County, on the Southern Railway, about 12 miles to the east. The bottoms of the valleys are about 2,500 feet above sea level, and the mountain peaks or knobs in the immediate vicinity rise to a height of 3,000 or 3,500 feet.
In the gravels of Caler Fork Valley pieces of crystals of red corundum were picked up by the people of the district, which led to the driving of two or three tunnels with the expectation of striking the vein and finding the corundum in sufficient quantity for commercial purposes. Work in this direction was soon abandoned, and for a number of years there were only prospecting and a little mining for the red corundum for gem purposes.
Systematic search, however, finally revealed the fact that ruby corundum was to be found in the gravels of Caler Fork Valley for a distance of 3 miles. In 1895 the American Prospecting and Mining Company, of New York, bought out the old claims and began work on a systematic basis. The property owned by the company is a large tract on both sides of Caler Fork of Cowee Creek and nearly all the land in the northern part of the watershed of Mason Branch, a total area of about 5,000 acres.
The gravels in which most of the rubies have been found are covered by soil averaging about 2 feet in depth, but varying from 1 to 5, and they are about 3 feet higher than the present alluvial gravel of the stream. Pl IV, A, is a view of one of the gravel beds that is being worked for rubies, just west of the company's office. The gravel in this part of the valley, which is overlain with 3 to 5 feet of soil, is composed of waterworn masses of quartz and small pebbles of gneiss and quartz, and is much cleaner in appearance than the gravels a mile farther up the creek, at In Situ Hill, where most of the mining was carried on during 1898. Fifty feet above the level of this gravel another bed was discovered at In Situ Hill which carried ruby corundum.
In washing these gravels for the rubies, hydraulic processes have been used very similar to those used in the West in washing gold-bearing gravels. All the soil, as well as the gravel, is washed into a short line of sluice boxes (a of Pl. IV, B) which lead into a large sieve box (b of Pl. IV, B), where the large pieces of rock and bowlders are removed and most of the dirt and fine gravel is washed out. They are then shoveled into a rocker (c of Pl. IV, B), where they are further cleaned and concentrated, the final concentration of the rubies being done by hand.
No basic magnesian rocks or serpentine derived from them, which which most of the corundum of North Carolina occurs, have been found in this valley. Corundum Hill and the Ellijay corundum regions are, however, less than 10 miles to the south.
Although in many respects the occurrence of the rubies and their associated minerals in the Cowee Valley is similar to the occurrence of the ruby in Burma, no limestone has been found near the alluvial deposits, the nearest point at which limestone has been found being at Cullowee Gap, about 8 miles to the southeast.
The country rock of the district is a gneiss, of a gray fine-grained variety, which has a great many small garnets disseminated through it. The rock for the most part is in a highly decomposed condition, but there are small exposures of the undecomposed rock in many places. The gravels which the rubies are found rest on a soft saprolitic rock which is the results of weathering of the basic silicate rocks in place. By means of shafts and of the workings at the gravel washings it has been shown that at a depth of 35 feet or more these saprolitic rocks contain fragments of the undecomposed rock and pass into such rocks as eclogite-amphibolite and hornblendic gneiss.
A narrow dike of hornblendic eclogite a few feet in width is exposed near the present workings of the company and can be traced for about 100 yards.
No rubies have been found in the undecomposed rock, but at In Situ Hill small rubies of a rather pale color were found in a narrow band of saprolitic rock. This band was, however, cut off by slickensides so that it could not be followed in any direction. There are four parallel slickensides that have been exposed at one place in the workings, the general direction of the slickensides being N. 75 E. Some of these are 70 feet in length and of unknown depth. It is very evident that there has been a great deal of disturbance in this immediate vicinity through the breaking of the rock masses by faulting, the ready influx of water having caused the reduction of the rocks to their saprolitic condition.
In washing the gravels and bodies of saprolitic rock, masses of undecomposed rock have been uncovered, and in the center of these nodules of the pure hornblende rock have been found. The saprolite bordering these nodules often contains particles and crystals of corundum.
Less than 2 miles to the east of In Situ Hill, beyond Betts Gap of the Cowee Mountains, corundum of a gray to bluish color, but highly crystallized, has been found in hornblende-gneiss. One mile a little north of west, at the Sheffield mine, pink corundum has been found in amphibole-schist. (See pp. 57-59.)
An association of corundum peculiar to this locality is with the garnet rhodolite. Corundum and garnet (almandine and rhodolite) not only occur constantly together in the saprolitic material and in the gravels, but corundum crystals have been found that bear the impression of the garnet. By means of wax a mold was taken of these impressions, and they were shown to be either the dodecahedron or trapezohedron. On the other hand, some of the ruby crystals when broken are seen to have a rhodolite garnet inclosed, and the garnet can often be seen in the transparent ruby crystal and the cut gem.
The peculiarities which distinguish this garnet from the ordinary occurrences of the species are its variety of shades and tints, for the most part similar to those belonging to the rhododendrons and roses; its surprisingly small amount of coloring matter; its gem-like transparency; its freedom from internal imperfections, microscopic inclusions, and striae, the characteristic imperfections of common garnets; also its remarkable brilliancy when cut as a gem. There is but one variety of garnet now known which approaches it, when in gem form, in this last respect, and that is the green demantoid of Siberia, which often vies with the diamond in its luster and dispersive effect upon light. Most garnets are beautiful only by transmitted light, and then exhibit only dark shades of color, but these new garnets give most beautiful effects of brilliant and varied coloring by reflected light alone, thus proving the uncommon purity and great clearness of this new material.
As has been said, there is no limestone in this immediate vicinity, and these rubies were probably derived from an amphibolite or eclogite. The usual tabular form of the crystals is one that seems to be characteristic of the gem corundum when found in igneous rocks.
The Cowee Creek rubies frequently contain inclusions, some of which are very minute, known to jewelers as "silk," and these give rise to a cloudiness or sheen in the polished gem. Some gems from this mine have been cut that were 3 or 4 carats, free from inclusions, of fine color, and transparent. A great many smaller ones have been cut that are perfect gems. In color and brilliancy these gems are equal to the Burma ruby, and if the percentage of the unflawed, transparent material increases but little, this new field will be a worthy rival to the Burma field. A considerable percentage of the transparent material is often very badly flawed by cracks due to parting and injured by the inclusions of rutile or menaccanite, so that the percentage of perfect stone from this mine is small. This, however, is true of the rubies from the Burma field also, for a large proportion of the rubies on the market to-day are usually more or less flawed with parting cracks.