Cummingtonite

Image

Brownish-colored sprays of cummingtonite needles, from near West Chesterfield, western Hampshire County, western Massachusetts, USA

© (C) 2017 James St. John (via Wikimedia Commons). CC-BY-2.0

Properties

Formulas ☐{Mg,FeII}2{Mg,FeII}5Si8O22(OH)2, ☐Mg2Mg5Si8O22(OH)2
Abbreviation Cum, Cum
Variant Fe2+
Classifications Mg-Fe-Mn amphibole, Cummingtonite-Grunerite (series), Minerals containing OH
Luminescence emitter OH
IMA Status Approved/redefined (IMA 2012 s.p.)
Search other databases webmineral.com, mindat.org, rruf.info, mineralienatlas.de, Handbook of Mineralogy, American Mineralogist Crystal Structure Database
Related materials Anthophyllite, Proto-anthophyllite
Tags Hydroxide , Mineral, Silicate

Composition

Element Atoms
H 2
Si 8
☐ 1
O 24
Mg 7
Total: 42

Reference

Reference
Lines Spectra Images
Burns & Strens 1966 2 0 0