Usually when these two species occur as replacement pseudomorphs in nature, it is a more thin-style of dyscrasite crystals altering to silver. However, in this rare case, robust and textbook, elongated, orthorhombic crystals of black dyscrasite, to 3 cm in length, have been pseudomorphed to pure silver. Unusual and impressive! The piece is extremely massive at 250 grams, and complete all around. I like it because it is so very different than the usual more gracile-looking pseudomorphs we usually see from this old locale. I am told that most of them were collected during the Soviet era of mining here, and this is surely an older specimen. ex. Dale Armstrong pseudomorph collection.