Encyclopedia

Cummingtonite

Also found in: Dictionary, Wikipedia.

cummingtonite

[′kəm·iŋ·tə‚nīt]
(mineralogy)
(Fe,Mg)7Si8O22(OH)2 A brownish mineral that crystallizes in the monoclinic system; usually occurs as lamellae or fibers in metamorphic rocks.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Cummingtonite

 

a mineral from the series of monoclinic amphiboles. The chemical composition is (Mg, Fe)7[Si4O11]2 (OH)2; admixtures of Ca, Al, Mn, and Na are common. The Mg-rich members are called cupfferite; the more ferruginous ones are called griinerite. Cummingtonite forms fibrous aggregates or radiating, columnar masses of brownish gray to dark brown color. It has a hardness of 5.5–6 on the mineralogical scale; its density ranges from 3,100 to 3,600 kg/m3. Cummingtonite is a characteristic mineral of metamorphic schists. It is also encountered in contact-metasomatic skarns and metamorphogenetic ore deposits.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
Mentioned in
References in periodicals archive
Of particular interest to this study is a hydrothermally derived assemblage composed of spessartine, rhodonite and asbestiform Mn-rich cummingtonite (Pires, 1977).
A crystal fragment free of cummingtonite inclusions was embedded in epoxy resin, polished and carbon-coated.
Ca-Mg-Fe-rich rhodonite from the Morro da Mina mine, Conselheiro Lafaiete, Minas Gerais, Brazil
Cummingtonite occurs as an accessory mineral in granodiorite in the district.
Famous Mineral Localities: DAL'NEGORSK PRIMORSKIY KRAY RUSSIA
[ ] Cummingtonite, [ ][Mg.sub.7][Si.sub.8][O.sub.22][(OH).sub.2], mon., dimorph.
The second list of additions and corrections to the Glossary of Mineral Species (1995)
Cummingtonite: possibly an erroneous characterization by XRD of gossan-like material from the Vanna Fault.
The Gold Quarry mine, Carlin-trend, Eureka County, Nevada
Copyright © 2003-2025 Farlex, Inc Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.