A fine and aesthetic, highly lustrous cluster of gray calcite crystals beautifully accented with sparkly, iridescent marcasite from the famous Brushy Creek Mine of Missouri's Viburnum Trend. A second generation of highly lustrous, nearly transparent, gray calcite coats the first generation of calcite and partially envelopes the marcasite on several of the calcite crystals. The super, 5.5 cm, doubly terminated, scalenohedron in the front, with the recessed bed of iridescent marcasite and an interior phantom on the left side is stunning. Ex. Karl Warning Collection and from an older, 1960s-1970s era Dallas collection.