MOHS RatingMOHS RatingGemstoneMineral Group10Diamond9Ruby , SapphireCorundum8TopazTopaz7.5EmeraldBeryl7.5AquamarineBeryl7AmethystQuartz7AmethystQuartz6.5Peridot5.5 - 6.5Opal3OnyxYou May Also Like...Metal Melting Point ChartKarating Up and Down ConversionsTips for Measuring Your Finger for Ring SizeHow to Measure Your Finger for Ring SizeDiamond Millimeter Size to Carat Weight Conversion ChartColorWire Gauge, MM, Inch Conversion ChartStone Weight Estimation Formula