The relative hardness of a mineral can best be tested by
Ascratching the mineral across a glass plate
Bsqueezing the mineral with calibrated pliers
Cdetermining the density of the mineral
Dbreaking the mineral with a hammer
Ascratching the mineral across a glass plate
Bsqueezing the mineral with calibrated pliers
Cdetermining the density of the mineral
Dbreaking the mineral with a hammer