The Deluxe Hardness Pick Set from Mineralab is unique in that, unlike other mineral hardness testing tools that use minerals or crystal points, Mineralabs picks are made of metals and alloys of hardness values equal to 2 through 9 on Mohs hardness scale. And because the picks are made of metal, they are easily ground to sharp points which will not break off and which can be easily sharpened Why measure the hardness of a mineral? Because hardness is an important and quantifiable physical characteristic of a mineral and in your effort to identify an unknown mineral.