Need help identifying this mineral in ROCKS, MINERALS and FOSSILS Posted September 6, 2019 1 hour ago, fuss said: Have you tried a streak test? I haven’t tried a streak test. I’ve never done a streak test before so I’m not 100% sure how. Should I just rub in on a piece of tile? Uncoated tile as in the back of a flooring tile, correct? Does it matter if the “rock” portion rubs it, or would we want the “metallic” part to rub? I don’t think I could easily rub the metallic part flat against a tile because the rock portion curves around it a bit. I might be able to rub the edge though.