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Cobaltocalcite  (Spherocobaltite)
Current inventory:  1 gem
 

Chemistry:  CoCO₃

Discovered in 1877;   IMA status: Valid (pre-IMA; Grandfathered).
Cobaltocalcite is named for its cobalt content and that it is a dimorph of Calcite. Spherocobaltite is named from the Greek sphaira, for sphere, plus cobalt, alluding to its spherical crystal habit and composition. The name Calcite is derived from the Latin calx, meaning lime.

Classification

Mineral Classification:

Carbonates

Strunz 8th Ed. ID:

5/B.02-70

5 : Nitrates, Carbonates & Borates
B : Waterfree carbonates without unfamiliar anions
02 : Calcite group

Crystal Data

Crystallography:

Trigonal-Hexagonal - Scalenohedal

Crystal Habit:

Crystals uncommon, rhombohedral, flat discoidal, modified, to 5 mm; commonly compact radiated, concentric, spherical, massive, and in crusts.

Twinning:

Observed

Physical Properties

Cleavage:

[1011] Perfect, [1011] Perfect, [1011] Perfect (perfect rhombohedral)

Fracture:

Subconchoidal

Tenacity:

Brittle

Moh's Hardness:

3.0 - 4.0

Density:

4.10 - 4.13 (g/cm³)

Radioactivity:

Not Radioactive

Optical Properties

Color:

Pink, Rose red, Gray brown, Black

Transparency:

Transparent to Translucent

Luster:

Vitreous to Adamantine

Refractive Index:

1.885 - 1.600  Uniaxial ( - )

Birefringence:

0.2850 (very high)

Dispersion:

Strong

Pleochroism:

Dichroic: O = violet-red; E = rose-red

Occurances

Geological Setting:

A rare accessory mineral in hydrothermal cobalt-bearing mineral deposits.

Type Locality:

Daniel Mine, Neustädtel, Schneeberg District, Erzgebirge, Saxony, Germany

Year Discovered:

1877

View mineral photos:

Cobaltocalcite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Cobaltocalcite, also known as Spherocobaltite, is a dimorph of Calcite. It is a rare and beautiful mineral and very rare gem. It is usually found in shades of pink from pale pink to rose red, to deep pinkish red. Current sources are Morocco, Spain and Congo (Zaire).
 

  
Cobaltocalcite gems for sale: