The varieties known by the name of Beryl are found principally in Siberia and Brazil : in the former country it occurs in the granite district of Nertsehinak and also in the Uralian and Altai Mountains, sometimes very large crystals, prisms having been found upward; of a foot in length. In the granitic mountains of Odon Tchelon, in Datiria, three very interesting mines occur at different elevations in the mountain ; in the lowest are found, irregularly disseminated through a mass of semi-decomposed gmnito mixed with ferruginous clay and nodules of Wolfram, prismatic crystals of Beryl of a greenish yellow colour, rarely exceeding one inch in length. Some hundred feet higher occurs the second mine in a vein of micaceous clay, from which the most valuable crystals are obtained ; their colour is of a pale but pure green, and their size frequently considerable. The third mine is situated in a vein of white indurated clay on the summit of a mountain ; in this mine the varieties are usually of a pale greenish blue, but sometimes they are found of a pure but pale sky-blue. They are here remarkably transparent. Imbedded crystals and massive varieties are also found at Limoges, in France ; near Zwiesel, on the Rabenstein, in Bavaria ; at Fimbo and Broddbo, near Fahlun, in Sweden; and likewise in some of the tin-mines in Saxony and Bohemia.
An enormous specimen is also described in Silliman's ' Journal' as having been found at Acworth in New Hampshire, United States. Its dimensions am stated to be 4 feet in length and 54 inches across the lateral planes, and the weight to be 238 pounds.
Specimens of Beryl have also been found in several of the primary districts of Ireland ; those from the granite of the Mourne Mountains, in the county of Down, are the finest. In this locality they are asso ciated with topaz, black quartz, felspar, and mica. In Scotland it is found in the granite at Rubeslau quarry, near Aberdeen, and also in broken pieces in the sand of the rivers of that county.
The value of the Emerald depends not only on its size, colour, and brilliancy, but also on its being free from flaws, by which this gem is frequently greatly deteriorated in the eye of the jeweller. The follow ing is the rate at which varieties of a fine colour and free from fissures may be procured, as stated by Beudant :— A stone of 5 grs. from 100 to 120 francs.
„ 8 „ 240 francs.
„ 15 „ 1500 „ Pl 24 2400 ,