256 A POPULAR TREATISE ON GEMS.
into violet; sometimes, by looking through in one direction, the red color changes into a blue color.
2. Indicolite (Brazilian sapphire), of an indigo, lazulite, or Prussian blue color.
3. Brazilian tourmaline (Brazilian emerald), of a grass-green or olive-green color.
4. Ceylonian tourmaline (Ceylon chrysolite), of a greenish-yellow color.
5. Electric schorl, of a yellowish, reddish, liver, or blackish brown color.
Tourmaline
occurs in rocks, such as granite in layers and gangues, and in
boulders; it also occurs in the beds of rivers, and the localities are
Siberia, St. Gothard, Ceylon, Brazil, Sweden, Saxony, and Moravia. In
the United States, tourmalines are abundant, but there are very few
localities of the better varieties, as those at Paris in Maine, and Chesterfield and Goshen in Massachusetts.
The
specimen of a crystal of rubellite, from Paris, Me., on the
frontispiece, is a perfect prism, is dark, red on the inside and dark
green on the outside, and belongs to Prof. Charles U. Shepard, of New
Haven, who exhibited it in the New York Exhibition in 1853. There are
several beautiful green and red transparent tourmaline crystals, from
the same locality, in the mineralogical museum of Yale College, from
the collection of the late Baron Lederer, Austrian consul in this city.
The
yellow tourmaline, from Ceylon, is but little inferior to the real
topaz, and is often sold for that gem. The green tourmaline, when
transparent, is often highly prized. '
The Siberian red tourmaline, called .siberite, is cut in cabochon, and exhibits then a milk-white chatoyant lustre.
The
black tourmaline is called schorl. The localities of tourmaline are
quite • numerous: large size black tourmalines are found in Greenland
at Hovelberg, in Bavaria
