MOHS+HARDNESS+SCALE

=== The hardness of various rocks and minerals can be used as an another method of identification. In the 19th. century, a German mineralogist- Friedrich Mohs, devised a scale of hardness for minerals. ===

Moh's Hardness Scale:

 * === Hardness  === || ===  Mineral  === || ===  Scratched by . . . .  === ||
 * == 1  == || ==  talc  == || ====  soft pencil lead  ==== ||
 * == 2  == || ==  gypsum  == || ====  fingernail; blackboard chalk  ==== ||
 * == 3  == || ==  calcite  == || ====  copper penny  ==== ||
 * == 4  == || ==  fluorite  == || ====  iron nail; brass  ==== ||
 * == 5  == || ==  apatite  == || ====  steel knife blade  ==== ||
 * == 6  == || ==  feldspar  == || ====  window glass; steel file  ==== ||
 * == 7  == || ==  quartz  == || ====  flint sandpaper  ==== ||
 * == 8  == || ==  topaz  == || ====  spinel  ====
 * (available in rock shops) ** ||
 * == 9  == || ==  corundum  == || ====  emery sandpaper  ==== ||
 * == 10  == || ==  diamond  == || ====  carborundum sandpaper  ==== ||