Pyrite - Varieties

Varieties

Cattierite (CoS₂) and Vaesite (NiS₂) are similar in their structure and belong also to the pyrite group.

Bravoite is a nickel-cobalt bearing variety of pyrite, with >50% substitution of Ni2+ for Fe2+ within pyrite. Bravoite is not a formally recognised mineral, and is named after Peruvian scientist Jose J. Bravo (1874–1928).

Synthetically, materials MX₂ with a pyrite structure can be made in the lab with for M a whole series of elements from the Mn column of the d block all the way to the Zn column and for X the chalcogenides S, Se or Te. For most of these systems it is also possible to make continuous solid solution series, so that the Bravo's geological findings are hardly surprising. From a chemical point of view the mineral is therefore likely to vary considerably in composition, depending on which elements were available during its formation.