Brown and Flame-Coloured Stones
Hardness. Specific Gravity.
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), 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
