Mineralogists classify hardness according to Moh's hardness scale which ranks hardness from 1 (talc) to 10 (diamond).
(Mineralogists; classify; hardness) (Moh's hardness scale; ranks; hardness; from 1 (talc) to 10 (diamond)
Mineralogists Moh's hardness scale
classify ranks
hardness
hardness from 1 (talc) to 10 (diamond