Arsenopyrite-Marcasite with Calcite and Muscovite

Minas da Panasqueira, Aldeia de São Francisco de Assis, Covilhã, Castelo Branco, Cova da Beira, Centro  Portugal (2004)

Specimen size: 11.7 × 6 × 3.8 cm = 4.61” × 2.36” × 1.50”
Main crystal size: 2.3 × 2 cm = 0.91” × 0.79”