Bronzite
Bronzite is a member of the
Enstatite is magnesium silicate, MgSiO3, with the magnesium partly replaced by small amounts (up to about 12%) of Fe+2. In the bronzite variety, (Mg,Fe)SiO3, the iron(II) oxide ranges from about 12 to 30%, and with still more iron there is a passage to
Like enstatite, bronzite is a constituent of many
Ornamental usage
Bronzite is sometimes cut and polished, usually in convex forms, for small ornamental objects, but its use for this purpose is less extensive than that of hypersthene[citation needed]. It often has a more-or-less distinct fibrous structure, and when this is pronounced the sheen has a certain resemblance to that of cats-eye. Masses sufficiently large for cutting are found in the norite of the Kupferberg in the Fichtel Mountains, and in the serpentine of Kraubat near Leoben in Styria. In this connection mention may be made of an altered form of enstatite or bronzite known as bastite or schiller spar. Here, in addition to schillerization, the original enstatite has been altered by hydration and the product has the approximate composition of serpentine. In color bastite is brown or green with the same metallic sheen as bronzite. The typical locality is Baste in the Radauthal, Harz, where patches of pale greyish-green bastite are embedded in a darker-colored serpentine. This rock when cut and polished makes an effective decorative stone, although little used for that purpose.[1]
References
- ^ a b c d public domain: Chisholm, Hugh, ed. (1911). "Bronzite". Encyclopædia Britannica. Vol. 4 (11th ed.). Cambridge University Press. p. 641. One or more of the preceding sentences incorporates text from a publication now in the
- ^ ISBN 0-471-80580-7
- ^ Jackson, Everett D., The Chromite Deposits of the Stillwater Complex, Montana in Ore Deposites of the Unitrd States, 1933-1967 (The Graton-Sales Volume) Vol. 2, pp. 1495-1509, 1968