Aegirine-augite

Image

Jet-black, lustrous aegirine crystals perched dramatically against a plate of albite matrix, covered by a sparkling microscopic druse of albite or perhaps quartz. Ex. Charlie Key. Specimen from Mt Malosa, Zomba District, Malawi. Size: 5.3 x 3.6 x 2.8 cm.

© Photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0

Properties

Formula (Ca,Na)(FeIII,Mg,FeII)Si2O6
Abbreviation Aeg-Aug
Classification Clinopyroxene
IMA Status Approved/redefined (IMA 1988 s.p.)
Search other databases webmineral.com, mindat.org, rruf.info, mineralienatlas.de, Handbook of Mineralogy, American Mineralogist Crystal Structure Database
Crystal symmetry Monoclinic, Point group 2/m, Space group C2/c (#15)
Tags Mineral, Silicate

Composition

Element Wt%
Na 2.52
Mg 5.33
Ca 13.18
Fe 12.24
Si 24.63
O 42.09
Total: 99.99