Dragon Scale Calcite with Marcasite – Brushy Creek Mine, Missouri, USA

A dramatic calcite with marcasite specimen from the Brushy Creek Mine, Reynolds County, Missouri, USA.

Many amazing calcites have been unearthed from the Viburnum Trend mining district but perhaps none are as impressive as the "dragon scale" crystals. Like this specimen, the calcite has a distinctive smoke gray colouration of its scalenohedral crystals caused by several generations of growth. After the original calcites formed they were later coated with chalcopyrite, marcasite or other sulphides. Finally, another generation of calcite overgrew the sulphides, encasing them, and creating the dark colouration. Exposed sulphides tend to be sparkling and iridescent providing additional interest to the already-dramatic calcites.

This is a large specimen, weighing just shy of 3 kg! It is actually the smaller, but more aesthetic, of the two "dragon scales" I acquired from Bill Rouslin's immense collection. It is composed of several scalenohedral calcite crystals tightly packed and partially intergrown creating a wonderful natural sculpture. All of the crystal edges and terminations are complete with no significant damage. The piece appears to be a "floater" with no obvious contact but one cleaved corner (not affecting any crystals). Note the colour-zoning within the calcites showing yellowish-gray, translucent edges giving way to darker gray interiors with a waxy overall luster.

Many of these were mined by professional specimen-collectors Mike New and Joe Kielbaso in the late 1980s and are we ever glad they did! For calcites, "dragon scales" are amongst the most collectible and difficult to obtain in this size and quality.

Minerals: Calcite, Marcasite
Locality: Brushy Creek Mine, Reynolds County, Missouri, USA
Crystal System: Calcite – Trigonal; Marcasite – Orthorhombic
Mineral Class: Calcite – Carbonate; Marcasite – Sulfide
Provenance: Ex Bill Rouslin #453
Dimensions: 17 × 12 × 14 cm