the.com/hardness
the measure of how much a material refuses to be scratched, dented, or talked into compromise
diamond kingTops the Mohs scale at a flawless 10
scratch testMohs ranks minerals by which scratches which
water credHard water is just dissolved calcium and magnesium
steel proofRockwell hardness presses diamonds into metal to score it
diamond vs diamondOnly a diamond can scratch another diamond