Composition: CaCO3
Crystal System : Trigonal
Colours: Colourless, white, grey, cream, pale-green, pink, orange, red
Lustre : Vitreous
Hardness (H) : 3
Specific Gravity (S.G) : 2.71


Abundant, and widespread throughout the Tsumeb deposit.


  • Hypogene
  • Supergene
  • Country Rock
  • 1st Oxidation Zone
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Notable Finds

Aesthetic examples of crystallised calcite appear to have been most abundant in the second and third oxidation zones. Early collections contain notably few examples of calcite and, while this might partly reflect the collecting prejudices of the time, there is a clear implication that attractive calcite specimens were scarce in the upper levels of the mine. Collectable calcites were commonly encountered at depth, however, including the distinctive specimens from two named pockets: (1) the so-called “ice-cream pocket”, discovered in 1977 and believed to be from the second oxidation zone, comprising very pale pastel-green rhombs of calcite, but with a sugary surface texture, suggesting either a degree of recrystallisation or (more likely) a replacement of dolomite (?). (2) the so-called “crystal palace”, a very large walk-in pocket of rhombohedral calcites associated with conichalcite, discovered in 1990 on 43 Level in the third oxidation zone (Gebhard, 1999).

Paragenetic and General Notes

Calcite is almost ubiquitous at Tsumeb, occurring as a component of the host-rocks, as an alteration product of (hypogene) mineralisation (calcitisation), and as the result of (supergene) oxidation processes in the secondary mineral assemblage. The latter process has generated a vast variety of habits, colours and associations, with crystals up to 200 mm. Gebhard (1999) notes that "Calcite is the most common mineral at Tsumeb and is associated with nearly all other minerals." Rhombohedral crystals are very common, while scalenohedral forms are relatively rare.

Calcite has been reported to form pseudomorphs after the following minerals: cerussite (rare); mimetite (rare).

The following minerals have been reported to form pseudomorphs after calcite:  conichalcite (rare); descloizite (rare, doubtful status); dolomite (common, often as epimorphs); galena (rare); mottramite (rare); smithsonite (rare, doubtful status).