Mineral necessarily constant for all sides, which is a function of its structure; crystallographic weakness renders some directions softer than others. An example of this property exists in kyanite, which has a Mohs hardness of 5½ parallel to [001] but 7 parallel to [100]. The most common scale of measurement is the ordinal Mohs hardness scale. Defined by ten indicators, a mineral with a higher index scratches those below it. The scale ranges from talc, a phyllosilicate, to diamond, a carbon polymorph that is the hardest natural material. The scale is provided below: Lustre indicates how light reflects from the mineral's
Temagamite of Wyoming. Temagamite Temagamite is a bright white palladium mercury telluride mineral with a hardness of on the Mohs scale. Its chemical formula is PdHgTe. It was discovered at the Temagami Mine on Temagami Island, Lake Temagami in 1973, and it represents a rare mineral in the Temagami Greenstone Belt. It occurs as microscopic inclusions within massive chalcopyrite at Temagami in association with other rare tellurides: merenskyite, stützite, hessite and an unnamed Pd-Hg-Ag telluride. In addition to the discovery locality, it has been reported from the Stillwater igneous complex in Montana and the New Rambler copper–nickel mine in the Medicine