Leisure hours among the gems

by Augustus C. Hamlin

At Haddam, in Connecticut, beautiful crystals of beryl have been discovered; and one of these of fine green color, an inch in diameter and several inches in length, was preserved in the cabinet of Colonel Gibbs. Professor Silliman possessed another fine one, seven inches in length.

The mountains in Colorado have yielded some fine specimens. But the finest of the beryl species come from Russia. In the Ural Mountains the crystals are small, but of fine color; in the Altai Mountains they are very large and of a greenish-blue; but in the granitic ledges of Odon Tchelon in Daouria, on the frontier of China, they are found in the greatest perfection. They occur on the summit of the mountain in irregular veins of micaceous and white indurated clay, and are greenish-yellow, pure pale-green, greenish-blue, and sky-blue. The chief matrix of the beryl all over the world is graphic granite, but it may occur in other rocks. The light green stones of Limoges, in France, appear in a vein of quartz traversing granite. At Royalston we observed them to spring seemingly from the felspar and project into smoky quartz, becoming more transparent as they advanced into the harder stone.

The beryl possesses the same crystalline form and specific gravity as the emerald, but its hardness, especially in the blue and white varieties, is sometimes greater. They are both silicates of alumina, and the only perceptible difference in the two stones is in the color. Cleaveland thought that as the emerald and beryl had the same essential characters, they might gradually pass into each other; and Klaproth, finding the oxides of both chrome and iron in one specimen, was led to take the same view. The crystals of true emerald are almost always small, with the exception of those found in the Wald district in Siberia, whilst those of the beryl vary from a few grains to more than a ton in weight. The crystals of both are almost invariably regular hexahedral prisms, sometimes slightly modified. Those of the beryl we sometimes find quite flat, as though they had been compressed by force; then again they are acicular and of extraordinary length, considering their slender diameter. Sometimes their lateral faces are longitudinally striated, and as deeply as the tourmaline, so that the edges of the prism are rendered indistinct. Other crystals are curved, and some perforated in the axis like the tourmaline, so as to contain other minerals. Sometimes they are articulated like the pillars of basalt, and separated at some distance by the intervening quartz. These modified forms give rise to curious speculations as to their formation and origin. If we admit the action of fire (which is improbable), then the separation may be easily explained; but if we insist that they were deposited in the wet way and by slow process, how can we account for the dislocation? “By electricity,” whispers a friend,—“by telluric magnetism, that wonderful unexplained and mysterious force which has caused the grand geological changes of the globe, and is still at work.”

Sometimes the crystals of beryl are of two distinct colors, but generally they are of one color, often shading into white at either extremity. They may exhibit the richest golden-yellow, or a light cerulean blue, or a clear sea-green like those described by Pliny, now called aqua-marines. “Qui viridatem puri maris imitantur.”

One distinction between beryl and quartz is afforded by the appearance of its fracture. A crystal of beryl breaks into smooth planes, the faces of which are at right angles to the axis of the prism; while the fracture of the surface of broken quartz is invariably conchoidal.

Blue beryls were highly prized by the ancients. Beautiful specimens are found in the glens of the Mourne Mountains in Ireland. But finer gems are brought from the granite district of Nertschinsk, in Siberia, and also from various localities in the Uralian and Altaian Mountains, where the Romans were supposed to have obtained them in early times.

Its name is derived from the Persian “belur,” which the Romans changed into “beryllus.” Sometimes it occurs of a rose color. A few have been found at Elba and one at Haddam by Colonel Gibbs. One of the most beautiful specimens of beryl known was discovered in Siberia. It consisted of a magnificent crystal of smoky quartz, in the base of which appeared several fine crystals of beryl, of an exquisite yellowish-green and greenish-blue.

In the princely collection of Mr. Vaux, of Philadelphia, may be seen a crystal of beryl from the Mourne Mountains of Ireland, two inches in length by five eighths of an inch in diameter. It is of a celestial blue color, much deeper in hue at one extremity than at the other. But the gem of this collection among the beryls is a specimen purchased in Russia, in 1875. It is a six-sided prism nine inches in length and six inches in circumference. The color is of a rich oily green, and several inches of its upper extremity is transparent, while the rest is translucent. It rests upon a mass of granite, and is a specimen of extraordinary size and beauty.

Mr. Clay of the same city has a remarkable prism of Siberian beryl two inches in diameter, which exhibits a tint of celestial blue externally but which appears of a decided green hue in its interior.

At the Centennial Exhibition Brazil exhibited a fine crystal of a warm celadine green color. Russia displayed some very beautiful specimens of the yellow, green, and blue beryls from Siberia. Some very beautiful crystals of emerald, both solitary and fixed in the matrix, were also exhibited from the same country.