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Purpurite

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Purpurite
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Purpurite from Namibia
General
CategoryPhosphate minerals
Formula
(repeating unit)
Mn3+PO4
Strunz classification8.AB.10
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPnmb
Identification
Formula mass149.91 g/mol
ColorBrownish black, violet, dark pink, dark red, reddish purple
Crystal habitMassive to granular
Cleavage[100] [001] perfect
FractureBrittle - uneven
Mohs scale hardness4-5
LusterEarthy
Streakred
Specific gravity3.2 - 3.4
Optical propertiesBiaxial (+) 2V 38°
Refractive indexnα = 1.850(2) nβ = 1.860(2) nγ = 1.920(2)
Birefringenceδ = 0.070
Other characteristicsnon-radioactive, non-magnetic, non-fluorescent.
References[1][2][3]

Purpurite is a mineral, manganese phosphate, MnPO4 with varying amounts of iron depending upon its source. It occurs in color ranges from brownish black via purple and violet to dark red.[2]

Purpurite forms a series with the iron-bearing endmember heterosite, FePO4.[3]

See also

References

  1. ^ Mineralienatlas
  2. ^ a b "Purpurite". Webminerals. Retrieved 2009-06-06.
  3. ^ a b Mindat