Calcite Group from Indonesia

A calcite group from Indonesia. The cluster geometry of this piece shows a particularly dense arrangement of individual crystals, an indication of slow nucleation speed during growth.

Slow nucleation produces few, large crystals; fast nucleation produces many, small ones. Dense clusters like this piece document a specific solution supersaturation constellation: highly supersaturated solution with many simultaneously nucleating microcrystals.

The Indonesian karst geology offers ideal conditions for such crystal clusters; the cave solution comes into contact with fissure cavities at different supersaturation values.

Mohs 3 makes calcite susceptible to scratches. Acid cleaning is absolutely to be avoided.

An Indonesian collector's item with dense nucleation cluster geometry and documented karst mineralization history.