Epitactic Arsenopyrite-Marcasite with Siderite, Calcite and Muscovite

Minas da Panasqueira, level 2, Aldeia de São Francisco de Assis, Covilhã, Castelo Branco, Cova da Beira, Centro  Portugal (1997)

Specimen size: 13.7 × 10.7 × 8.2 cm = 5.39” × 4.21” × 3.23”
Main crystal size: 7 × 2.6 cm = 2.76” × 1.02”