Shungite

Named after a village in Russia nearest to the location in which it was discovered, shungite is a rather interesting mineraloid made up of over 98 percent carbon. Geologists believe that shungite may be Precambrian in age, formed nearly 2 billion years ago! This mineraloid is typically a lustrous, fairly reflective silver to black that exhibits a conchoidal fracture pattern similar to that of obsidian or glass. Shungite lacks any crystalline structure, which is why it is classified as a mineraloid.