| 释义 |
cummingtonite, n. Min.|ˈkʌmɪŋtənaɪt|
[f. the name of Cummington, a town in Massachusetts, U.S.A., where it was first found: see -ite1.]
A basic silicate of magnesium and ferrous iron, (Mg, Fe)7Si8O22(OH)2 , that is an amphibole mineral similar to anthophyllite but monoclinic and with more iron, and that occurs as fibres and lamellae in metamorphic rocks.
1824C. Dewey in Amer. Jrnl. Sci. & Arts VIII. 59 Cummingtonite, I have given this name to a mineral found by Dr. J. Porter in Cummington. 1966McGraw-Hill Encycl. Sci. & Technol. III. 623/1 The observed ranges of composition of cummingtonite and anthophyllite overlap considerably... Cummingtonite is optically positive and thus distinct from the other monoclinic amphiboles. 1977Lancet 9 July 80/2 The Duluth water supply contained mineral fibres resembling asbestos, which were shown to be an asbestos amphibole, cummingtonite-grunerite. 1989Jrnl. Petrol. XXX. 42 The occurence of cummingtonite instead of garnet in the amphibolite is also consistent with low-pressure hornblende-granulite grade metomorphic conditions. |