'The greatest difference in hardness between 2 Mohs scale neighbors is between corundum (9) & this (10)'
diamond
ROCKY: The greatest difference in hardness between 2 Mohs scale neighbors is between corundum & this
The greatest difference in hardness between 2 Mohs scale neighbors is between corundum & this
The greatest difference in hardness between 2 Mohs scale neighbors is between corundum & this
ROCKY
diamond
ROCKY