Calcite with Marcasite

Older (circa 1990-2000) Brushy Creek material is quite distinctive and, despite new production of good quality, will always be recognized by the alternating matte and glassy luster and the selective marcasite deposition. This single crystal , with two very small sisters, would go quite nicely in a single crystal collection.

Locality: Brushy Creek Mine, Reynolds County, Missouri

Composition: calcium carbonate coated with iron sulfide