Olmiite
Olmiite
Published: June 2014
Modified: October 2021
Olmiite was officially named as a new species in 2006. It is the Manganese dominant analog of poldervaartite. It is named after the Italian mineralogist Filippo Olmi. The only known location where olmiite is found is the N’Chwaning II mine, Kalahari field, Republic of South Africa.
General Information
Common Name
Olmiite
Species
Olmiite
Transparency
Translucent-Transparent
Refractive Index
1.663-1.694
Birefringence
0.031
Optic Character
Biaxial
Optic Sign
Positive
Polariscope Reaction
Aggregate (AGG), Doubly Refractive (DR)
Fluorescence
SWUV: Inert to Deep red
Pleochroism
None
Hardness
5-5.5
Streak
White
Toughness
Poor
Luster
Pearly, Vitreous
Stability
Brittle
Fracture
Uneven, Irregular
Cleavage
None
Chemical Name
Calcium manganese silicate hydroxide
Chemical Formula
CaMn[SiO3(OH)](OH)
Crystal System
Orthorhombic
Chemistry Classification
Silicate
Olmiite Colors
-
Brown -
Gray -
Orange -
Pink -
White -
Yellow
Countries of Origin
Unknown; South Africa
Care
Normal care