Please help me identify this rock. I’ve found it in a cave.
closed as off-topic by arkaia, Fred, trond hansen, Peter Jansson, hichris123♦ Jan 7 at 6:34
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Please review our rock identification guidelines to provide the missing information so that your question is both answerable and useful to new users." – hichris123
It is almost certainly the mineral pyrite, based on the colour and the shape of the crystals. If so, rubbing it on unglazed porcelain will leave a black streak. It could also be chalcopyrite but that tends to look more yellow. It would help to know where exactly it was found.