Aragonite

A classic hexagonal crystal revealing emerging central crystals from one termination. Under UV (LW) this should react yellow, as the terminations weakly did, but in the photo there is a red reflection, and for the life of me I cannot re-create it. No flash, just a UV light.

Locality: Los Molinillos-La Vacariza, Minglanilla, Cuenca, Castile-La Mancha, Spain

Composition: calcium carbonate