MOH's Scale of Hardness

Moh's (Mohs) scale of hardness is the most common method used to rank gemstones and minerals according to hardness. This scale grades minerals on a scale from 1 (very soft) to 10 (very hard). This is the Traditional Scale of Hardness Collection and a Test Kit. Includes Streak Plate, Coin, Glass Plates, Nail and nine specimens 1" X 1.5" number coded.