Truly spectacular in every sense, these old classics are unique specimens. They turn up rarely, in old collections. An iridescent coating of marcasite nearly covers all of two milky crystals of quartz, to 6.5 cm in length. The marcasite colors range from brassy yellow, to emerald green, to copper and magenta. I believe this to be one of the finer examples of this combination for its coloration, size, and aesthetics.