Location: Mina da Panasqueira, Covilhã, Castelo Branco, Portugal.
Rhombohedral crystal, translucent to opaque yellowish brown, good cleavage. Sample with 3.2 x 2.7 x 2.0cm. 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 schists and graywackes.