_Hardness._ _Specific Gravity._ (See Chapter VII.) (See Chapter VIII.) Carnelian (a variety of Chalcedony) 6-1/2 2.598-2.610 Diamond 10 3.502-3.564 Deep Red Garnet 7-1/4 3.40-4.50 Jasper 7 2.668 Opal (the "Fire Opal") 5-1/2-6-1/2 2.21 (average) Ruby 9 4.073-4.080 Rhodonite 5-1/2-6-1/2 3.413-3.617 Sapphire 9 4.049-4.060 Spinel Ruby 8 3.614-3.654 Topaz 8 3.500-3.520 Tourmaline 7-1/4 3.024 Zircon 7-1/2 4.70-4.88 PINK STONES. _Hardness._ _Specific Gravity._ (See Chapter VII.) (See Chapter VIII.) Beryl 7-3/4 2.709-2.810 Diamond 10 3.502-3.564 Ruby 9 4.073-4.080 Spinel 8 3.614-3.654 Topaz ("burnt" or "pinked"), see Chapter XIV., page 92 8 3.500-3.520 Tourmaline 7-1/4 3.024 BLUE STONES. _Hardness._ _Specific Gravity._ (See Chapter VII.) (See Chapter VIII.) 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 GREEN STONES.