Cerite
Appearance
Cerite | |
---|---|
General | |
Category | Silicate mineral group |
Formula (repeating unit) | (Ce,La,Ca)9(Mg,Fe+3)(SiO4)6(SiO3OH)(OH)3 |
Crystal system | Trigonal |
Crystal class | Ditrigonal pyramidal (3m) (same H-M symbol) |
Space group | R3c |
Identification | |
Color | Clove-brown with a reddish tinge; pale lavender-brown to colorless in thin fragments |
Crystal habit | Massive granular |
Cleavage | None |
Fracture | Uneven |
Mohs scale hardness | 5 to 5.5 |
Luster | Vitreous to resinous |
Streak | White to greyish white |
Diaphaneity | Subtranslucent to opaque |
Specific gravity | 4.7 to 4.86 |
Optical properties | Uniaxial (+) |
Refractive index | nω = 1.806 - 1.810 nε = 1.810 - 1.820 |
Birefringence | δ = 0.010 |
References | [1][2][3] |
Cerite is a complex silicate mineral group containing cerium, formula (Ce,La,Ca)9(Mg,Fe+3)(SiO4)6(SiO3OH)(OH)3.[2] The cerium and lanthanum content varies with the Ce rich species (cerite-(Ce)) and the La rich species (cerite-(La)).[4][5] Analysis of a sample from the Mountain Pass carbonatite gave 35.05% Ce2O3 and 30.04% La2O3.[2]
Cerite was first described in 1803 for an occurrence in Bastnäs in Västmanland, Sweden.[3] The lanthanum rich species, cerite-(La) was first described for an occurrence in the Khibina massif, Kola Peninsula, Russia in 2002.[6]
See also
References
- ^ Mineralienatlas
- ^ a b c http://rruff.geo.arizona.edu/doclib/hom/ceritece.pdf Handbook of Mineralogy
- ^ a b http://webmineral.com/data/Cerite-(Ce).shtml Webmineral (Ce)
- ^ http://www.mindat.org/min-931.html Mindat Cerite-(Ce)
- ^ http://www.mindat.org/min-26408.html Mindat Cerite-(La)
- ^ http://webmineral.com/data/Cerite-(La).shtml Webmineral (La)
External links
- Media related to Cerite-(Ce) at Wikimedia Commons