Alabaster

This stone type is formed by chemical precipitation of calcite in a similar manner to stalactites and stalagmites found in limestone caves but this process does not produce the large slabs required for dimension stone production.

Alabaster is also produced in a similar manner to travertine when carbonate-saturated water resurfaces at springs and the change in pressure and temperature results in the release of the carbon dioxide causing precipitation and crystallisation of the calcite. Its deposition in successive layers (along with minor mineral contaminants) gives rise to the banded appearance that the stone often shows in cross section. Alabaster is relatively soft with a Mohs hardness of around 3 (can be scratched easily with a knife).