Spherocobaltite

Spherocobaltite
Spherocobaltite from Peramea, Lérida, Catalonia, Spain
General
CategoryCarbonate mineral
Formula
(repeating unit)
CoCO3
IMA symbolScbt[1]
Strunz classification5.AB.05
Crystal systemTrigonal
Crystal classHexagonal scalenohedral (3m)
H-M symbol: (3 2/m)
Space groupR3c
Unit cella = 4.65, c = 14.95 [Å]; Z = 6
Identification
Formula mass118.94 g/mol
ColorMost commonly dark magenta red; pink to red, brown, brownish red, grey, greyish red, velvet-black (due to surface alteration)
Crystal habitEncrustations - forms crust-like aggregates on matrix, crystals uncommon: rhombohedral to discoidal
CleavagePerfect rhomboidal cleavage [2]
Mohs scale hardness4
LusterVitreous
StreakPink
DiaphaneityTransparent to translucent
Specific gravity4.13
Optical propertiesUniaxial (–)
Refractive indexnε = 1.600, nω = 1.885
Birefringence0.285
PleochroismDichroic: O = violet-red; E = rose-red
References[2][3][4]

Spherocobaltite or sphaerocobaltite is a cobalt carbonate mineral with chemical composition CoCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It crystallizes in the trigonal crystal system.

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Spherocobaltite on Mindat
  3. ^ Spherocobaltite at Webminerals
  4. ^ Spherocobaltite in Handbook of Mineralogy