2.521-2.795
Sapphire 9 4.049-4.060
Spinel 8 3.614-3.654
Topaz 8 3.500-3.520
Tourmaline 7-1/4 3.029
Zircon 7-1/2 4.700-4.880

YELLOW STONES.

_Hardness._ _Specific Gravity._
(See Chapter VII.) (See Chapter VIII.)
Amber 2-1/2 1.000
Beryl 7-3/4 2.709-2.810
Chrysoberyl 8-1/2 3.689-3.752
Chrysolite 6-7 3.316-3.528
Corundum (the yellow variety known
as "Oriental Topaz" [not "Topaz"],
see below) 9 3.90-4.16
Diamond 10 3.502-3.564
Garnets (various) 6-1/2-7-1/2 3.4-4.5
Hyacinth (a form of Zircon) 7-1/2 4.7-4.88
Quartz (Citrine) 7 2.658
Sapphire 9 4.049-4.060
Spinel 8 3.614-3.654
Topaz (for "Oriental Topaz," see above) 8 3.500-3.520
Tourmaline 7-1/4 3.210

BROWN AND FLAME-COLOURED STONES.

_Hardness._ _Specific Gravity._
(See Chapter VII.) (See Chapter VIII.)
Andalusite 7-1/2 3.204
Diamond 10 3.502-3.564
Garnets (various) 6-1/2-7-1/2 3.40-4.50
Hyacinth (a form of Zircon), see below 7-1/2 4.70-4.88
Quartz (smoke coloured) 7 2.670
Tourmaline 7-1/4 3.100
Zircon (Hyacinth) 7-1/2 4.70-4.88

RED AND ROSE-COLOURED STONES.

_Hardness._ _Specific Gravity._
(See Chapter VII.) (See Chapter VIII.)
Carnelian (a variety of Chalcedony) 6-1/2 2.598-2.610
Diamond