Fluorite with Pyrite

Fluorite with Pyrite from Solís, Asturias, Spain, measuring 64 × 44 × 36 mm and weighing 146 grams. A solid piece from Spain's north-coast mining province.

Fluorite, calcium fluoride CaF2, isometric, occurs widely as a gangue mineral in hydrothermal vein and karst-related deposits, and Asturias's long-worked mining districts, historically centred on coal, iron and base metals, have produced Fluorite from several such vein systems, with Pyrite, iron disulfide FeS2, a common accessory sulfide in the same mineralising fluids.

Asturian Fluorite is seen less often in collections outside Europe than the region's volume of mining might suggest, which makes a named-locality piece like this a useful addition for anyone building a broader Spanish mineral suite. This piece carries a double provenance, the David Vince Collection and Willyama Minerals.