Part 2

Beryl (hardness: 7.5-8 Mohs) Beryllium aluminum silicate Specific gravity: 2.63-2.91

Emerald: Intense green or bluish green Aquamarine: Greenish blue or light blue Morganite: Pink, purple pink, or peach Heliodore: Golden yellow to golden green Red beryl: Raspberry red Goshenite: Colorless, greenish yellow, yellow green, brownish

Chrysoberyl (hardness: 8.5 Mohs) Beryllium aluminum oxide Specific gravity: 3.68-3.78

Chrysoberyl: transparent yellowish green to greenish yellow and pale brown Alexandrite: red in incandescent light and green in daylight Cat’s eye: usually yellowish or greenish

Corundum (hardness: 9 Mohs) Aluminum oxide Specific gravity: 3.96-4.05

Ruby: Intense red Sapphire: Blue

Diamond (hardness: 10 Mohs) Carbon Specific gravity: 3.51

Colorless to faint yellowish tinge, also variable

Feldspar (hardness: 6-6.5 Mohs) Two distinctly different alkali alumino silicates: the Plagioclase and the Alkali Feldspar Series Specific gravity: 2.55-2.76

Plagioclase Series— Labradorite: Colorful, iridescent, also transparent stones in yellow, orange, red, and green Sunstone: Gold spangles from inclusions of hematite Peristerite: Blue white iridescence

Alkali Feldspar Group— Orthoclase: Pale yellow, flesh red Amazonite: Yellow green to greenish blue Moonstone: Colorless; also white to yellowish, and reddish to bluish gray

Garnet (hardness: 6.5-7.5 Mohs) A group of silicate minerals Specific gravity: 3.5-4.3

Almandine: Orangy red to purplish red Almandine-spessartine: Reddish orange Andradite: Yellowish green to orangy yellow to black Demantoid: Green to yellow green andradite Topazolite: Yellow to orangy yellow Grossular: Colorless; also orange, pink, yellow, and brown Tsavorite: Green to yellowish green Hessonite: Yellow orange to red Pyrope: Colorless; also pink to red Chrome pyrope: Orange red Pyrope-Almadine: Reddish orange to red purple Pyrope-Spessartine: Greenish yellow to purple Malaia: Yellowish to reddish orange to brown Color-change garnet: Blue green in daylight to purple red in incandescent light Rhodolite: Purplish red to red purple Spessartine: Yellowish orange Uvarovite: Emerald green

Jade (hardness: 6 Mohs)

Nephrite Calcium magnesium silicate Specific gravity: 2.9-3.1

White, deep green, creamy brown

Jadeite Sodium aluminum silicate Specific gravity: 3.1-3.5

White, leafy and blue green, emerald green, lavender, dark blue green and greenish black, deep emerald-green

Lapis lazuli (hardness: 5-5.5 Mohs) A rock composed mainly of the mineral lazurite with variable amounts of pyrite (brassy flecks) and white calcite Specific gravity: 2.7-2.9

Deep blue, azure blue, greenish blue (bluish color with flecks of white and gold)

Opal (hardness: 5.5-6.5 Mohs) Hydrated silica Specific gravity: 1.98-2.25

White opal: Opaque, porcelain-like white material; colors resemble flashes or speckles Black opal: Flashes and speckles appear against black background Water opal: A transparent, colorless opal is the background for brilliant flashes of color Fire opal: Reddish or orange opal

Peridot [Olivine] (hardness: 7 Mohs) Magnesium iron silicate Specific gravity: 3.22-3.45

Olive to lime green

Quartz (hardness: 7 Mohs) Silicon dioxide or silica Specific gravity: 2.65

Coarsely crystalline varieties of silica— Rock crystal: Colorless Amethyst: Purple Citrine: Yellow to amber Morion: Black Smoky quartz or cairngorm: smoky gray to brown Rose quartz: Translucent pink Green quartz or praziolite: Green

Cryptocrystalline varieties of silica— Chalcedony and Jasper (variable) Agate: Bull’s eye agate, Iris or fire agate, Onyx, Sardonyx. Bloodstone or heliotrope. Carnelian. Chrysoprase. Moss agate. Plasma. Prase. Sard. Jasper.

Spinel (hardness: 8 Mohs) Magnesium aluminum oxide Specific gravity: 3.58-4.06