Blue gemstones
Hardness. Specific Gravity.
Beryl 7-3/4 2.709-2.810 Diamond 10 3.502-3.564 Dichorite (Water Sapphire) 7-7-1/2 4.049-4.060 Disthene (Kyanite) 5-7 3.609-3.688 Iolite (Cordierite) 7-1/4 2.641 Lapis lazuli 5-1/2 2.461 Sapphire 9 4.049-4.060 Topaz 8 3.500-3.520 Tourmaline 7-1/4 3.160 Turquoise 6 2.800
