86
GEMS AND PRECIOUS STONES
many
thousands of specimens have been brought from Alaska in the past ten
years. Some time ago the United States man-of-war " Corwin" visited the
place, and brought away specimens, which are now in the United States
National Museum.
The
beautiful and rare species, known as ouvarovite or chrome garnet, was
first described as occurring in the United States by Prof. Charles U.
Shepard, who found it in minute, nearly transparent, emerald-green
crystals, 1/10 inch in diameter, at Wood's chrome mine, Lancaster
County, Pa. Ouvarovite is found in large quantities at Orford, Canada,
adjoining Newport, Vt., on Lake Memphremagog, sometimes in masses
measuring over 1 foot across. The crystals, however, are very small,
rarely over 1/16 inch
in diameter, though usually of good color. The white garnet of that
locality, described by Dr. T. Sterry Hunt, although not in crystals, is
identical with the fine crystals found at Wakefield, Canada, and has
been cut into gems. The Wakefield ouvarovite is much finer than the
Orford variety. It has been described by Waldemar Lindgren as occurring
in small crystals associated with a chromiferous chlorite related to
kotscheubeite, from Green Valley on the American River in California.
The crystals are of very fine color, but not transparent enough for
gems.1 Schorlomite, which has recently been referred to the
garnet group, is really a titaniferous garnet, and occurs at Magnet
Cove, Ark. It is generally penetrated by white crystals of apatite, but
at times it is free from all foreign matters, and very compact,
breaking with a bright conchoidal fracture. On cutting it yields a dead
black stone, having a lustre not quite as metallic as that of rutile,
but rather between it and black onyx. As it occurs in sufficient
quantity, it is suggested as a mineral that will afford a new and fine
mourning gem. Stones can be cut of any size up to perhaps about 20
carats, as the mineral is found of sufficient size. The first stone cut
was over 6 carats in weight. Prof. George A. Koenig, of the University of Pennsylvania, describes a
titaniferous garnet from southwestern Colorado, and also gives an
analysis of so-called schorlomite from Magnet Cove, Ark., which he
finds to be titaniferous garnet.'
1 See Proc. Cal. Acad. Sci. II., Vol. I, Dec, 18S7. *Proc. Acad. Nat. Sci., Phil., 18S6, p. 355.
