Glossary of Karst and Cave Terms
1. A relatively rare form of calcium carbonate (CaCO3), chemically identical to the more common calcite but of orthorhombic crystal form. Its pure form is metastable in the cave environment, where calcite forms preferentially. It is relatively abundant in some caves due to the presence of impurities, notably strontium, that distort the carbonate lattice and favor aragonite growth. The commonest form seen in caves as small radiating crystals (anthodites) that develop in humid caves, where surfaces are covered by a moisture film but not by flowing water. 2. A mineral composed of calcium carbonate, CaCO3, like calcite but differing in crystal form . 3. An unstable orthorhombic carbonate mineral, CaCO3 .