Pyrostilpnite is the rare, monoclinic dimorph of Pyrargyrite, the well-known and highly coveted Silver mineral. These long and slender crystals reach up to 3 mm, and are well protected in a shallow pocket. The luster and golden-red color are both excellent, and typical for the species. Quite scarce, this old-time specimen is from the famous mines at St. Andreasberg, and is out of the British Museum via trade to Kay in the 1980's per her label. Legitimate, validated, pyrostilpnite of ANY quality is exceedingly uncommon. Although small, these are quite fine and gorgeous under the loupe.