Richterite. Wilberforce, Monmouth Township, Haliburton County, Ontario, Canada.
General
Category
Inosilicates
Formula (repeating unit)
Na(NaCa)Mg5Si8O22(OH)2#
IMA symbol
Rct[1]
Strunz classification
9.DE.20
Crystal system
Monoclinic
Crystal class
Prismatic (2/m) (same H-M symbol)
Space group
C2/m
Identification
Color
Brown, yellow, red, or green
Crystal habit
Prismatic; acicular or asbestiform
Twinning
Simple or multiple parallel to {100}
Cleavage
Perfect
Fracture
Uneven, brittle
Mohs scale hardness
5–6
Luster
Vitreous
Streak
Pale yellow
Diaphaneity
Transparent to translucent
Specific gravity
3.0–3.5
Optical properties
Biaxial (−)
Refractive index
nα = 1.615 nβ = 1.629 nγ = 1.636
Birefringence
δ = 0.021
Pleochroism
Strong: pale yellow, orange, and red
2V angle
68° measured
References
[2][3][4][5]
Richterite is a sodium calcium magnesium silicate mineral belonging to the amphibole group. If iron replaces the magnesium within the structure of the mineral, it is called ferrorichterite; if fluorine replaces the hydroxyl, it is called fluororichterite. Richterite crystals are long and prismatic, or prismatic to fibrous aggregate, or rock-bound crystals. Colors of richterite range from brown, grayish-brown, yellow, brownish- to rose-red, or pale to dark green. Richterite occurs in thermally metamorphosed limestones in contact metamorphic zones. It also occurs as a hydrothermal product in mafic igneous rocks, and in manganese-rich ore deposits. Localities include Mont-Saint-Hilaire, Quebec, and Wilberforce and Tory Hill, Ontario, Canada; Långban and Pajsberg, Sweden; West Kimberley, Western Australia; Sanka, Myanmar; and, in the US, at Iron Hill, Colorado; Leucite Hills, Wyoming; and Libby, Montana. The mineral was named in 1865 for the German mineralogist Hieronymous Theodor Richter (1824–1898).
Richterite is a sodium calcium magnesium silicate mineral belonging to the amphibole group. If iron replaces the magnesium within the structure of the...
titanium-rich aluminium-poor phlogopite; potassium- and titanium-rich richterite; low aluminium diopside; and iron-rich sanidine. A variety of rare trace...
in Libby, Montana, did have tremolite asbestos as well as winchite and richterite (both fibrous amphiboles)—in fact, it was formed underground through essentially...
to danger by mining vermiculite contaminated with asbestos, typically richterite, winchite, actinolite or tremolite. Vermiculite contaminated with asbestos...
content is between 48.9% and 51.7%. Common groundmass includes potassium-richterite. Wyomingite has also been found at two locations in Australia: West Kimberley...
have good resistance to chemicals and can be used in microwave ovens. Richterite glass-ceramics are used for high-performance tableware. Fluorosilicate...
colleagues identified phlogopite and potassium richterite (in which potassium is substituted for sodium in richterite) as two of the most important minerals involving...
troilite at Toluca; daubreelite, krinovite, roedderite, high albite, richterite, chromite (Canyon Diablo); and jadeite, chromite and chlorite (Burma)...
the hexagonal system and forms tiny hexagonal plates associated with richterite and serpentinitized olivine of mafic xenoliths in the lamproite host rock...
, Hawthorne, F.C. (1993) The OH-F substitution in Ti-rich potassium-richterites: Rietveld structure refinement and FTIR and micro-Raman spectroscopic...
120. 1995 B.E. Leake, C. M. Farrow & R. Townend. K-poor titanian fluor-richterite from near Nullagine, Western Australia. American Mineralogist, 80, 162–4...
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