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Ch. 10: Chiastolite, Cyanite, Datolite, Staurolite, ... Fluorite

Ch. 10: Chiastolite, Cyanite, Datolite, Staurolite, ... Fluorite Page of 364 Ch. 10: Chiastolite, Cyanite, Datolite, Staurolite, ... Fluorite Text size:minus plus Restore normal size   Mail page  Print this page
178                             GEMS AND PRECIOUS STONES IN THE
phia, Pa., in reddish-brown crystals ; and at the lead mine in Can­ton, Ga. At the Parker Mine, Cherokee County, N. C, it occurs in large, coarse, single crystals and twins; also along Persimmon, Hanging Dog, and Bear Creeks, Madison County, and Tusqui-tee Creek, Clay County. In the last-mentioned places staurolite is found in argillaceous and talcose slates. Some staurolite macles similar to a chiastolite, from Charlestown, N. H., are described by Dr. Charles T. Jackson. These pass by insensible shades or gradations into andalusite macles.
Isopyre is found in small veins from 1 to 3- inches in width in the magnetic iron at Dickinson Mine in Ferremonte, three miles from Dover, N. J. In color it very nearly resembles the darker green jasper, or, in other words, bloodstone without the red spots. It is used as a gem in the cabinets of collectors. Its hardness is 6-o to 6.5.
Pectolite was found in quantity among the Esquimau imple­ments collected by the United States Signal Service at Point Bar­row, Alaska, and examined by Prof. Frank W. Clarke ;' it was at first supposed to be jade, but on examination proved to be a new and interesting variety of compact pectolite, in two varieties, one pale apple-green, the other dark green. The specific gravity of the pale-green variety was 2.873, that of the dark-green 3.092. This forms an interesting and unexpected addition to the list of gem stones. During 1887 a massive white pectolite of unusually dense structure, and susceptible of a high polish, was announced by William P. Blake as occurring in Tehama County, Cal., in masses of considerable size. In a letter to the writer he gives the follow­ing description of it: "It occurs in a vein, and is broken out in rough tabular masses, from 2 to 3 or more inches in thickness, but it is reported that much larger masses can be obtained. It is exceedingly tough and hard to break. The fractured surfaces are irregular, without cleavage, but have a silky lustre, and a crypto-crystalline structure is exhibited in extremely fine inseparable fibres, which are radial, curved, and interlaced, and are, perhaps, imbedded in a silicious magma, but the fibres constitute the bulk of the mass. Color, white, with a delicate shade of sea-green; translucent. Exposed or weathered portions lose their porcelain-
1 Am. J. Sci., III., Vol. 28, p. 21, July, 1884.
Ch. 10: Chiastolite, Cyanite, Datolite, Staurolite, ... Fluorite Page of 364 Ch. 10: Chiastolite, Cyanite, Datolite, Staurolite, ... Fluorite
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