Jewelry, Gems, & Minerals/recognize of mineral
i found in old mine one rock that i think is diamond is very hard and i try to cut it with granter but i cant can you please help me to understand what is it?
Just from the photo I would guess this is a piece of quartz. It doesn't have the crystal habit of diamond. I would need to test it to be sure. Quartz is hard enough to scratch many things including glass. Diamond forms in a volcanic pipe in a rock called blue ground. There is only one place in the US that has diamond in it, "The Crater of Diamonds State Park" in Arkansas. You might take it to a jeweler or to a lapidary to identify it.