Pyrochroite
Black pyrochroite crystals with tan pyroaurite in a calcite matrix
General
CategoryMineral
Formula
(repeating unit)
Mn(OH)2
Strunz classification4.FE.05
Dana classification6.2.1.3
Crystal systemTrigonal
Space groupHexagonal Scalenohedral
H-M symbol: 3m (3 2/m)
Unit cella = 3.31Å, c = 4.74Å, Z = 1[1]
Identification
CleavagePerfect on {0001}
TenacityElastic
Mohs scale hardness2.5 to 3
LusterPearly on cleavages[1]
Adamantine [2]
StreakWhite[2]
DiaphaneityTranslucent, opaque
Density3.23 to 3.27 g/cm3
Optical propertiesUniaxial (-)
Refractive indexnω = 1.680 to 1.681
nε = 1.720 to 1.723
Birefringenceδ = 0.040
PleochroismVisible
Ultraviolet fluorescenceNon-fluorescent[2]
References[3]

Pyrochroite is a mineral with formula Mn(OH)2.

Description

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Pyrochroite has been found in association with alabandite, barite, calcite, dolomite, galaxite, hausmannite, lead, manganosite, rhodochrosite, and tephroite.[1]

History

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Distribution

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Pyrochroite has been found in Canada, China, Ghana, Japan, Namibia, Romania, Russia, South Africa, Sweden, Switzerland, the UK, the US, and along the Mid-Atlantic Ridge.[3]


References

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  1. ^ a b c "Pyrochroite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved June 28, 2012.
  2. ^ a b c "Pyrochroite". Webmineral. Retrieved June 29, 2012.
  3. ^ a b "Pyrochroite". Mindat. Retrieved June 28, 2012.

Bibliography

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  Media related to Pyrochroite at Wikimedia Commons