How do I calculate the hardness of my stone？

MOHs Scale

MOHs hardness scale or MOHs mineral scale was developed in 1822 by German mineralogist Fredrich Moh as a pratical method of comparing the hardness of different minnerals. The MOHs scale consists of ten readily available minerals arranged in order of their hardness. Basically, if the mineral being tested can be scratched by a mineral in the MOHs scale, then the test mineral is softer than that mineral. In return, if the mineral being tested can scratch a mineral listed in the MOHs scale, then the test mineral is harder than that mineral.