What is "zaccagnaite"

n. (context mineralogy English) A white hexagonal mineral composed of zinc, aluminium, carbon, oxygen, and hydrogen.

Zaccagnaite is a mineral, with a formula Zn Al C O(O H)·3 HO. It occurs as white hexagonal crystals associated with calcite in cavites in Carrara marble of the Italian Alps and is thought to have formed by hydrothermal alteration of sphalerite in an aluminium rich environment. It is named after Domenico Zaccagna (1851–1940), an Italian mineral collector.