Shades of Red.—Garnet, carnelian, chalcedony, rose quartz, corundum, tourmaline, spinel, ruby.
Shades of Brown.—Zircon, garnet, smoky topaz, axinite, jasper.
Colorless.—Diamond, sapphire, spinel, zircon, topaz, rock crystal, moonstone.
Lustre.
Well polished precious stones display a decided lustre, which assists in determining their species.
The following is a list of some precious stones and their lustre:
Adamantine.—Diamond, zircon.
Resinous.—Garnet.
Vitreous.—Emerald, ruby, spinel.
Waxy.—Turquois.