How do you tell if a rock is a diamond?
How do you tell if a rock is a diamond? The only hardness test that will identify a diamond is scratching corundum. Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale. If your suspected diamond crystal can scratch corundum, then there is a good chance that you found a diamond. But NO OTHER HARDNESS TEST will identify a diamond.
The only hardness test that will identify a diamond is scratching corundum. Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale. If your suspected diamond crystal can scratch corundum, then there is a good chance that you found a diamond. But NO OTHER HARDNESS TEST will identify a diamond.