Phosgenite

A complex large crystal, almost 6 cm long, of glassy Phosgenite with a ferruginous matrix attached. What first appears to be damage are areas of growth interference with the matrix, resulting in several glassy, mirror-bright plateaus interrupted by crevasse-like depressions, themselves lined with later generation millimetre-sized Phosgenite crystals. This specimen is from the world famous Monteponi mine at Iglesias on the Italian island of Sardinia. The specimen displays good levels of transparency; mirror bright prism faces and mirror-smooth prism faces while, contradictory, being heavily striated. It comes with a handwritten old label and a U.S. National Museum (Division of Mineralogy) label.