From: Mina da Panasqueira, Covilhã, Castelo Branco, Portugal.
 
 
Black crystalline cluster of Marmatite (variety of Sphalerite) sprinkled with small cream-colored Siderite rhombohedral crystals, short transparent prismatic Quartz crystal with 3.7 x 3.5 x 1.8cm next to a small hexagonal prism of blue-green Fluorapatite. Sample with 3.7x3.5x1.8cm. Formed in mineralized veins of quartz, sulfides, wolframite, cassiterite, micas, fluorite, carbonates, among others, associated with the generation of a greisen dome by granitic intrusion in Paleozoic schists and graywackes.