Leisure hours among the gems

by Augustus C. Hamlin

But one locality thus far has been discovered in the United States or even in North America, and this occurs in North Carolina. For several years previous to the year 1880, Mr. J. A. Stephenson, a collector of minerals, had obtained in Alexander County a number of beryls and crystals of transparent minerals which had the shape of beryl with a tint of the emerald hue, also other crystals of acicular form which exhibited the true color of the finest Granada specimens of emeralds.

Some of these minerals were shown in 1880 to William E. Hidden, a young naturalist then engaged in searching the mineral belts of North and South Carolina and Georgia for rare minerals. The beauty of these specimens led the young enthusiast to make a thorough search for the parent ledge; and, after a few weeks of earnest labor in cutting deep ditches in the soil near the spot where a number of crystals had been found, he was rewarded with the discovery of the original deposit in a rock of gneiss. In this rock, in which felspar preponderates, he found implanted in open pockets and lenticular fissures crystals of emeralds, quartz, rutile, monazite, beryl, and also many crystals of long and slender shapes which appeared to be diopside, but which exhibited colors of white, yellow, and green of the most beautiful emerald hues. The mineral which appeared to be diopside was submitted to the examination of the distinguished chemist, J. Lawrence Smith, who soon pronounced it to be a new form of spodumene, and named it Hiddenite after the young explorer. Since then the explorations have been continued, and have yielded many very beautiful specimens of both the emerald and the hiddenite. At the depth of thirty-three feet below the surface of the rock several pockets were discovered which yielded some beautiful emeralds and hiddenites. They occurred at the bottom of the pockets, just as the finest crystals of tourmaline are found in the cavities of the granite ledges at Mount Mica in Maine. Twelve of these pockets were found within an area of forty feet square, extending to thirty feet in depth. The largest crystal of emerald found was more than three inches in length and three quarters of an inch in breadth, but its color, although of the true emerald hue, is, however, rather faint. Some of the smaller crystals are of much deeper tint, and resemble the pure specimens from Granada. But the most interesting treasures of the mineral kingdom revealed by this exploration were the crystals which analysis proved to be composed of a silicate of alumina and lithia, otherwise known as spodumene. Some of these crystals were white or light yellow, others were of a rich yellow hue shading into brown, while others exhibited the purest prismatic green of various depths of hue. In some of the green crystals the color has been uniform, while in others it is more intense at one end of their extremities.

Quite a number of the crystals and their fragments have been cut and polished into gems which rival, by their lustre and beauty of color, the best of the South American emeralds. On account of their extreme rarity, as well as their beauty, they have been sought for by amateurs, and have commanded high prices. As the field of deposit thus far known is quite limited, we fear that the yield of this charming mineral will not meet even the demands of science.

Professor Cleaveland, who was one of the best authorities of his day, maintained more than half a century ago that emeralds which exhibited a lively and beautiful green hue were found in blasting a canal through a ledge of graphic granite in the town of Topsham in Maine. Several of the crystals presented so pure, uniform, and rich a green, that he ventured to pronounce them precious emeralds. But to-day we are unable to verify the assertion, or point to a single specimen similar in hue to the emerald from the above-mentioned locality.

The nearest approach to the emerald in color, with the exception of the incomparable green tourmalines from Maine, and the emeralds and hiddenites of North Carolina, are the beryls of North and South Royalston, in the State of Massachusetts. These beautiful stones exhibit the physical characteristics of emeralds, with the exception of the color, in which they differ very perceptibly. But to appreciate fully the difference in hue we must compare the two gems. Then the lively green of the beryl fades away before the overpowering hue of the emerald, whose rich prismatic green may be taken as the purest type of that color known to the chemist or the painter.

Several years ago we visited the localities in Massachusetts which were famous in the days of Hitchcock and Webster. We found that the beryls occurred in a very coarse granite, where the quartz appeared in masses and the felspar in huge crystals. These also occur in finer granite, and exhibit no indications of veins or connection with each other. They are few in number, and are soon exhausted by blasting, being generally very superficial. After removing several tons of the rock at the locality at North Royalston, where the beryls appear on the summit of the loftiest hill, our labors were at length rewarded with two beautiful crystals. One of them was a fine prism an inch in diameter, of perfect transparency and of a deep sea-green color, which, however, is far from being similar to the transcendent hue of the Granada emeralds, which exhibit an excess of neither blue nor yellow. The other was yellowish-green, resembling the chrysoberyls of Brazil.

Other but imperfect crystals were brought to light, some fragments of which exhibited the deepest golden tints of the topaz, and others the tints of the sherry-wine colored topazes of Siberia. Magnificent crystals have been found in these localities in times long past, and from the fragments and sections of crystals found in the débris of early explorations, we observed the wide range of color, and the deep longitudinal striæ which characterize the renowned beryls from the Altai Mountains, in Siberia. Lively sea and grass green, light and deep yellow, also blue crystals of various shades, have been found here.

At the quarries on Rollestone Mountain in Fitchburg, beryls of a rich golden color have been blasted out. Some of these approach the chrysoberyl and topaz in hardness and hue. Others so closely resemble the yellow diamond that they may readily be taken for that superior gem. The refractive power of these yellow stones is remarkable; and the goniometer will probably reveal a higher index than is accorded to all the varieties of beryl by the learned Abbé Haüy.

Beautiful transparent beryls have been found among the granite hills of Oxford County in Maine; and the late Governor Lincoln, nearly half a century ago, possessed a splendid crystal, quite three inches in length and of great purity and brilliancy. Some very beautiful transparent blue crystals of beryl have recently been found in the western part of Oxford County, Maine, which have yielded gems of considerable value. Probably active search for this mineral in this region will bring to light some charming specimens.

New Hampshire is famous for its gigantic beryls; and the localities of Acworth and Grafton have yielded some enormous crystals. One was removed by Mr. Alger, of more than a ton in weight; and a still larger one was observed by Mr. Hubbard, who estimated its weight at two and one half tons. These gross specimens are generally opaque, with patches of translucent or even transparent mineral on their sides. The regularity of their crystalline forms is also much impaired or distorted.