Covellite

This stone really IS rare: It comes from a closed mining area near Butte, Montana. It is probably the most unusual stone I've ever seen—It's a deep, metallic midnight blue all over, accented with faint streaks and confetti-like pieces of silvery pyrite. Covellite is relatively soft and is not suitable for hard-wear jewelry. All of the Covellite here was mined forty years ago or more; some material is from 1975.