Popular Science Monthly/Volume 28/April 1886/The Gems of the National Museum
|THE GEMS OF THE NATIONAL MUSEUM.|
THE collection of gems exhibited by the National Museum at the Cincinnati and New Orleans Expositions is now on exhibition at the rooms of the Museum in Washington. This much-needed accession, representing a small part of the appropriation for the World's Fair, promises to be one of the most attractive and instructive features of the museum. The large number of visitors who examined the collection, both at the fairs and in its present location, can testify to its interesting character. Although a mere beginning, it is the most complete public collection of gems in the United States. It is contained in two flat plate-glass exhibition-cases, the gems being neatly marked with printed labels, and arranged on velvet pads with a silk-rope border. The diversity, brilliance, and richness of Nature's brightest colors displayed render the whole effect a very attractive and pleasing one. The collection begins with a suite of glass models of the historical diamonds, followed by a series of diamonds in their natural state, among which is an interesting octahedron, eighteen carats in weight. These specimens are good illustrations of the form from South Africa, though of little commercial value as gems. One dozen other crystals from one quarter to one carat in weight complete a representative set of form and occurrence in that region. Next we have a very neat set of a dozen more crystals, small but choice, principally from India and Brazil, and formerly belonging to the Mallet collection. One of these is a perfect cube, a form peculiar to Brazil, while another is twinned parallel to the octahedron. Another stone of one carat is only half cut, and for comparison we have a stone of about the same weight completely cut.
Among the sapphires we find a carat, oblong stone of dark-blue color, from the Jenks mine, Macon County, North Carolina, which has yielded a few fair sapphires, yellow, violet, and blue, and a few rubies, some of the finest of which were in the Leidy collection; also the first stones found here, the dark-brown, asteriated sapphires, described in "Transactions of the New York Academy of Sciences," March, 1883, and two other cut stones weighing from four to eight carats. These all show a slight bronze play of light on the dome of the cabochon in ordinary light, but under artificial light they all show well defined stars, being really asterias or star-sapphires, and not cat's-eyes, as would seem at first glance. There are also two cut stones, light blue and light green, weighing one and two carats respectively, which, for light-colored sapphires, are perhaps, when cut, brighter than those from any other locality. The cutting of one of these gems has given it a remarkable luster. They are found in the sluice-boxes at and near Helena, Montana. Following are two broken crystals of the dark green sapphires from the quite recent find at the Hills of Precious Stones in Si am, beautifully dichroitic, being green and blue when viewed in different axes. An asteria of good blue color, measuring nearly one inch across, a beautiful two-carat ruby-asteria, and a small three-quarter-carat ruby, of fair color, complete the corundum gems
The series of spinels is well chosen and varicolored: it consists of a long two-carat stone of smoky-blue color; an oblong almandine-colored stone of three carats, an inky stone of one and a half carat, a half-carat ruby spinel of fair color, a pretty rubicelle of three quarters of a carat, and a suite of crystals of the ruby-colored spinel from Ceylon and Hurinah. We have also a cut Alexandrite (so called after the Czar Alexander I), from the original Russian locality. This is of fair color, but the wonderful Ceylonese gems of recent years have really given to this phenomenal variety of chrysoberyl, which changes from green to red under artificial light, its present high rank among gems. There is a six-carat typical chrysoberyl, finely cut (the chrysolite of the jeweler), truly, as the name indicates, golden beryl, and a dark-green one of that shade repeatedly sold as Alexandrite, though it does not change color by artificial light. A set of seven rough fragments from Brazil is instructive by comparison.
Among the beryls we have a flawed emerald of ten carats, that well illustrates the typical color, as does a pear-shaped drop of about the same weight and quality. There is also a crystal that has been in the institution for many years, labeled from New Mexico. It is evidently not from that locality, for no other such occurrence is on record, and we must suspect that the label is a misnomer, since the crystal has unmistakable signs of Muso (New Granada) origin. An emerald crystal two inches long, one of a series of minerals brought by Professor J. D. Dana from Peru when with the Wilkes Exploring Expedition, is historically interesting. It was purchased by him in the streets of Callao. In the same series are two good cut beryls, one six carats in weight, of a light-green color, another one-carat light-blue one from Royalston, Massachusetts, and perhaps the finest specimen ever found, at the Portland (Connecticut) quarries, fifteen carats in weight, and of such a rich, deep sea-blue color as almost to rival in splendor the matchless three-carat Brazilian blue-stone that is in the same case.
A fine blue crystal from Mourne Mountain, Ireland, is interesting for its locality and deep color. Stoneham, Maine, has contributed a two-carat white cut stone and a similar fragment; while Siberia is represented only by a common white stone of about six carats' weight.
Next comes a series of the emerald-yellow and yellowish-green varieties of spodumene (variety Hiddenite), embracing lithia emerald in the rough, and three cut stones of the same, weighing from a quarter to three-quarters of a carat, and varying in color from green to yellowish-green, from Stony Point, North Carolina; also a quarter-carat light-yellow and a one-carat golden-yellow spodumene of the variety resembling chrysoberyl, described by Pisani, of Paris, in "Comptes Rendus" for 1877, from Brazil. The white cut phenakite of three carats' weight, from Russia, is of rare occurrence, but has recently been found at two localities in Colorado.
The tourmalines include a dark-red gem (rubellite) of six carats' weight, and good color; two light-red ones of one half carat each, and a line dark-blue one (indicolite) of three eighths carat; four long bottle-green (called Brazilian emeralds) of two carats each; a half-carat white achroite; two olive-green stones of two carats each; and two sections of green crystals that have red centers. This difference of color between the outer and inner crystals is peculiar to tourmalines, as many as three colors being found in one crystal. All these are from Brazil. The well-known domestic localities are represented by an oblong, table-cut, light-green stone from Paris, Oxford County, Maine, that once held a conspicuous place in the collection of Dr. Joseph Leidy, which, unfortunately, had to be scattered. From Auburn, Maine, a locality quite recently discovered, we have a one-carat blue indicolite, two lavender-colored stones of one carat each, a light emerald-green stone of three quarters of a carat, and as handsome as an emerald by artificial light, and also a suite of several dozen loose crystals of various colors. The neighboring two-carat yellow and three-carat yellowish-brown cut stones are from Ceylon. The fine two-inch grass-green crystal and one-inch bluish-green crystal are also part of the treasure brought home by Professor Dana from the Wilkes Expedition of 1838-'42.
A six-carat blue and two-carat sherry-colored topaz from Siberia are exceedingly brilliant, but the domestic reputation is well sustained by the cinnamon-tinted fifteen-carat cut stone from Pike's Peak, Colorado, which is not surpassed in beauty by the brilliant white four-carat (Minas Novas) from Minas-Geraes, in Brazil. A series of crystals that have been "heated," follows, varying in color from dark pink fading into white according to the degree of calorification.
Among the garnets are ten flat, brilliant cut stones, four carbuncles, and six rose-colored, from Bohemia; six Tyrolese red garnets, two essonites (usually sold as hyacinths by the jewelers), four carats and a quarter carat from Ceylon, and a series, cut and uncut, from New Mexico, which furnishes the finest garnets in the world in point of color. In addition to these we notice a two-carat demantoid (green garnet or Uralian emerald) from Bobrowska River, Syssersk, in the Urals, and a brownish-green one-carat stone from the same locality.
From New Mexico we have a fine yellowish-green peridot or olivine, called chrysolite by the mineralogist, but not by the jeweler, and known as "Job's Tears" locally (from their pitted, tear-like appearance), while the Orient is represented by a beautiful olive-green cut stone.
From the zircons or jargoons we may single out for remark a number of small cut stones, yellowish-brown, pink, bluish-green, and white, the latter color being often produced by heating. Stones of this kind were at one time used for incrusting watches, which were then sold as diamond-incrusted. Next we observe a fine, rich, hyacinth-colored gem (the true hyacinth of the mineralogist), a long, two carat green, a yellowish-green, and a brownish-green three-carat stone, all from Ceylon. The two carat axinite from Dauphiny is one of the rarest of gems. A six-carat yellowish-green epidote from the Knuppenwand, the well-known locality in Tyrol, should be mentioned.
Here, too, is a one-fourth-carat idocrase from Ala, in Piedmont. This mineral, which received the name vesuvianite, because it is found among the formations in the lava at Vesuvius, is sold by the Neapolitan jewelers, and used to make the letters I and V in the manufacture of initial or sentimental pieces of jewelry. The same mineral is found at Sandford, Maine, and other localities here, but rarely in gem form.
Iolilite (dichroite, cordierite), or water-sapphire (saphire-d'eau), as it is also called, is here seen in the form of a flat-cut stone, of two carats' weight, from Ceylon, and a cube, one-fourth inch square, from Bodenmais, Bavaria. These are not comparable with one found at Haddam, Connecticut, that was worn as a charm by the late Dr. Torrey. This stone has dichroitic properties: if viewed in one direction it appears blue; if in another, pure white.
The five-carat titanite, or yellow sphene, is from the Tavetchthal, in the Tyrol. This gem shows the play of colors peculiar to the diamond. Specimens have also been found at Bridgewater Station, Pennsylvania. There are three long, yellowish-brown andalusites, of two, one, and three-fourths of a carat weight, at times so dichroitic that they have been offered in London as Alexandrites. These are from Brazil, where fine green ones are also obtained.
Next in order is a light-green diopside, from De Kalb, New York, a locality which has yielded twenty-carat gems, of rich oily-green color, equal to the one-carat cut stone from Ala, in Piedmont.
A small, long, one-carat cyanite, from Russia, is noteworthy, as is also the suite of opals, consisting of two noble cut stones, from Hungary, and a polished slab of the light matrix from the same place, beautifully mottled with opalescent spots; a set of over twenty gems, white, yellow, and brown, from Queretaro, Mexico; and two fair, noble opals from Honduras, together with a one-inch, lusterless cut stone; three pieces of blue opal, in the impure brown limonite, or ironstone matrix, from the Baricoo River, Queensland, Australia, termed opaline by the jewelers, and also a cut stone from the same locality.
Of turquoise, we have a bluish-green piece, one inch and a half long, cut into a flat cabochon stone, from Los Cerrillos, New Mexico, a fine suite of the mineral in the matrix, recently brought on by Major J. W. Powell, from New Mexico, and a set of twenty-four gems from Persia, showing all the characteristic gradations of color between blue and green; a curious half-inch cabochon cut stone, and a piece one inch long in the matrix, from Arabia, noticeable for the pleasing contrast of the bluish-green stone on the background of the chocolate colored matrix.
Hematite is exhibited, cut in the form of balls and in a cut intaglio, and a cut, one-carat rutile, from Alexander County, North Carolina; these so closely resemble the black diamond in color and luster as to have been mistaken for it when first found.
A dark, almost black hypersthene, from Norway, shows a pleasing bronze-like reflection on the dome of the cabochon. One of the most instructive of the series is a quantity of gem-gravel from Ceylon, containing sapphires of various colors, chrysoberyl, zircon, quartz, and other stones.
A series of the American stone, Thompsonite, found as pebbles in the Lake Superior region, presents some fine cut stones, with the circles from one fourth to three fourths of an inch across. A few large, polished pieces measure over one inch across. Some small pebbles of Lintonite found with the Thompsonite are also polished.
The quartz array is very instructive: it begins with a two-and-a half-inch Japanese crystal ball, and an eagle seal three inches high, of Russian cutting; cut citrines, cairngorm, and the so-called smoky, Saxon, or Spanish topaz, eleven of the dark-purple amethysts from Siberia, often wrongly called Oriental amethysts, and a set of seven from Brazil, show all the changes from light pink to dark purple.
Perhaps the most unique gem of the collection is a piece of amethyst that was found at Webster, North Carolina, and deposited here by Dr. II. S, Lucas. The present form is just such as would be made by a lapidary in roughly shaping a stone, preliminary to cutting and polishing it. It now measures seven centimetres in length, six centimetres in width, four centimetres in thickness, and weighs 136·5 grammes. It was turtle-shaped when found, and this was said to have been the work of prehistoric man. This shape was unfortunately destroyed by chipping it to its present form. It is perfectly transparent, being slightly smoky and pale at one end, and it also has a smoky streak in the center. This coloring is peculiar to the amethyst, however. There are also a three-quarter-inch yellowish quartz cat's-eye from Ceylon, and a three-carat green one from Hoff, Bavaria, and a native Indian necklace from Ceylon, composed of numerous yellowish quartz cat's-eye beads of about three carats each.
We have, then, a beautiful series of the brown-quartz cat's-eyes, so-called crocidolite cat's-eyes (also called tiger-eyes), in fine slabs, balls, buttons, etc., which is really a combination of crocidolite fibers coated with quartz. This incasing renders it harder than unaltered crocidolite, which is to be seen here together with it. All these are from South Africa. Superb rutilated quartz (sagenite,flèche d'amour, Venus-hair stone, or Love's arrows), in the rough and in cut form, are from North Carolina. Rhode Island contributes black hornblende blades in quartz, and green actinolite in the same (the Thetis-hair stone of Dr. Jackson). The actinolite, when in straight layers in the quartz, occasionally forms a quartz cat's-eye, if cut across the fibers.
The large pieces of black onyx, chrysoprase, carnelian, and sardonyx, the series of agates, of various colors, are cut into a variety of forms; the tine three-inch-square slab of "gold quartz," of the jewelers, is from Grass Valley, California.
Fine avanturine quartz, with spangles of mica in a rich reddish-brown quartz, from Russia, vases of which are often worth thousands of dollars; and a line green avanturine, called imperial jade by the Chinese, and more esteemed by them than any of the true jades deserve attention. The series of fifteen small Indian mocha-stones is very attractive; the black, moss-like markings are relieved by the red spots in the gray body of the stone, thus presenting a surface beautifully diversified. A rich, brown, speckled jasper is worthy of notice. The two cut moldavites (Moravian bottle-glass), about one inch across, are of rare occurrence. They are transparent, dark-green obsidians, from Moravia, for which worthless green bottle-glass has sometimes been sold.
The two sun-stones from Norway—the largest one and a half inch long, the other a three-quarter-inch cut cabochon—are indeed line, but a cut stone of the same material, over one inch long, from Delaware County, Pennsylvania, is nearly equal to them. Labradorites are fully represented, some polished pieces being over one foot across, and a number showing the beautiful chatoyant colors to perfection.
Amber, yellow, transparent, and containing flies and other insects, is present in the form of cut stones and beads.
A rich, dark-brown cut aragonite from California, and the beautiful green, copper-colored Smithsonite (a zinc-ore), from Laurium, Greece, demand special notice. One is a cut cabochon over one inch high, the other an ideal piece of the natural mineral. We observe also a tine polished malachite from Siberia, and a dish of the highly prized dark-blue fluorite from Derbyshire, England, where it is familiarly known as "blue John." Vases of this material have often been sold for over one thousand dollars. A slab of the Persian lapis-lazuli, and one of the white-veined variety from the Peruvian Andes, well represent this species. A jade pendant, three inches long and of good color, is one of the sort made in Germany to sell in New Zealand as genuine aboriginal workmanship. Also a flat vase made of a light-green Chinese jade, and one of the small bracelets of the same material, which are put on the arms of girls in early childhood, and allowed to remain there until the natural growth of the arm fixes them so tightly that they can not be removed over the hand. A rich yellow flower chiseled out of serpentine, about four inches by two, is very pretty, as is a curious, fanciful, dragon-like, talc ornament from Southern India. Red, white, and mottled agalmatolite (Chinese figure-stone), from China, is interesting.
One of the finest specimens of its kind in the United States is a magnificent six-by-four slab of lumachelle ("fire-marble") of fossil origin, in which the color of the original shells is so deepened and intensified that it rivals the finest fire-opal. This comes from the old, exhausted locality of Carinthia, Germany. Of alabaster, we have white, yellow, and cinnamon-gray slabs; of fossil coral, a fine slab from Iowa City. The oölite limestone from Bristol, England, is curious; the surface is highly polished, presenting a white field flecked with dark-red. Beads of gypsum satin spar and a three-inch egg of the same material are from Bideford, England.
The collection ends with an eight-by-three slab of catlinite (Indian pipestone), from Coteau du Prairie, Pipestone County, Minnesota. The head delineated on it was carved by a Washington sculptor, and came into the museum with the Abert collection, which was given to the museum.
To the energy of Professor F. W. Clarke is due the credit of forming this most interesting series of gems.
- Gems are generally bought and sold by the weight, called a carat, which is equal to about 3·168 troy grains. It is usually divided, however, into four diamond or pearl grains, each of which is ·7925 of a true grain. Fractions of a carat are also known as fourths, eighths, sixteenths, thirty-seconds, and sixty-fourths. The weight of the carat formerly differed slightly in different countries, and this diversity finally led a syndicate of Parisian jewelers, goldsmiths, and gem-dealers, in 1871, to propose a standard carat. This was subsequently confirmed by an arrangement between the diamond-merchants of London, Paris, and Amsterdam, fixing the uniform value of the diamond (?) carat at ·205 grain.