Gemstones

• Name of stone [chemical composition]
  1. Colours
  2. # Mohs' scale of hardness; Type of crystals
  3. Uses

• Amber [Pine resin]
  1. Amber
  2. # 2-2.5; Crystals not clear
  3. Earrings, bracelets, necklasses, other jewelry, ornamental objects
• Amblygonite [Phosphates of aluminum, lithium, sodium, flourine]
  1. White
  2. # 6; Triclinic
  3. Collections
• Andalusite [Silicate of aluminum]
  1. Various colours
  2. # 7.5; Orthorhombic, pleochroic
  3. Spark plugs, ceramics
• Anglesite [Sulfate of lead]
  1. White, grey, blue, green, yellow
  2. # (n/a); Orthorhombic
  3. Collections
• Apatite [Fluorophosphate of calcium]
  1. Green, white, brown, yellow, blue, red
  2. # 5; Hexagonal; prismatic, translucent
  3. Source of phosphorus
• Aragonite or Tufa [Carbonate of calcium]
  1. Colourless, grey, white, yellow
  2. # 3.5-4; Orthorhombic
  3. Ornamental slabs, beads
• Axinite [Hydrous borosilicate of calcium, manganese, iron, aluminum]
  1. Brown, blue
  2. # 6.5-7; Triclinic, pleochroic
• Azurite [Hydrous carbonate of copper]
  1. Sky blue
  2. # 3.5-4; Monoclinic
  3. Paint pigment, cameos, ornaments
• Beryl [Silicate of beryllium, aluminum]
  1. Green (emerald), Blue/blue-green/grey (aquamarine), Colourless/gold/pink/yellow/yellow-green (precious beryl)
  2. # 7.5-8; Hexagonal, seldom perfect
• Chrysoberyl [Beryllium aluminum oxide]
  1. Yellow, green, brown
  2. # 8.5; Orthorhombic, twinned
  3. Jewelry
• Chrysocolla [Hydrous silicate of copper, aluminum]
  1. Green, blue
  2. # 2-4; Orthorhombic
  3. Jewelry
• Cordierite or Iolite [Silicate of magnesium, iron, aluminum]
  1. Violet blue, yellow grey, light blue
  2. # 7-7.5; Orthorhombic, twinned, pleochroic
• Diamond [Carbon]
  1. Colourless
  2. # 10; Cubic, clear or opaque
  3. Cutting and drilling; jewelry, electrical insulators, abrasive
• Diopside [Silicate of aluminum, calcium, iron, lithium, magnesium, manganese, sodium, or titanium]
  1. Green, black, brown, grey, white, colourless
  2. # 5-6; Monoclinic, appear to change shape when viewed from different angles
  3. Beads
• Dioptase [Silicate]
  1. Green
  2. # 5; Trigonal or rhombohedral, dichroic
  3. Small jewelry
• Dolomite [Carbonate of magnesium]
  1. Colourless, white, pink, yellow
  2. # 3.5-4.5; Trigonal, twinned
  3. Production of magnesium
• Dumortierite [Borosilicate]
  1. Deep violet to blue
  2. # 7; Orthorhombic, fluorescent, pleochroic
  3. Collections, decorative stone, fine ceramics, beads, sculptures
• Enstatite [Silicate of iron, magnesium]
  1. Brown, green
  2. # 5.5; Orthorhombic, very high melting point
  3. Gems; lining for kilns, ovens, furnaces
• Epidote or Pistacite [Hydrous silicate of calcium, aluminum, iron]
  1. Green, yellow, brown
  2. # 6-7; Rhombohedral, pleochroic
  3. Display jewelry
• Fluorite [Fluoride of calcium]
  1. Various colours, single or multiple
  2. # 4; Cubic, fluorescent
  3. Iron smelting; ceramics, optical lenses, collections, fluorine
• Garnet [Variety of silicates]
  1. Green (demantoid, uvarovite), Green/yellow/copper-brown (grossular), Orange to red-orange (spessartite), Red with brown (pyrope), Red with violet (alamandine)
  2. # 6.5-7.5; Cubic
  3. Jewelry
• Gypsum [Hydrated sulfate of calcium]
  1. Colourless, white, brown
  2. # 2; Monoclinic, twinned
  3. Plaster of Paris, plasterboards, cement, drywall, ornamental stone, jewelry
• Hematite [Oxide of iron]
  1. Red
  2. # 5.5-6.5; Trigonal
  3. Source of iron; ornamental stones
• Idocrase (See: Vesuvianite)
• Iolite (See: Cordierite)
• Jade [Silicate of sodium, aluminum, iron]
  1. Green, brown, violet
  2. # 6.5-7; Rarely in crystals, tough
  3. Knives, ornamental slabs, gems, jewelry
• Jet [Carbon]
  1. Black, dark brown, yellow
  2. # 2.5-4; (crystals n/a)
  3. Jewelry
• Kyanite [Silicate of aluminum]
  1. Blue
  2. # 6-7; Triclinic, pleochroic
  3. Spark plugs, gems
• Lazulite or Lapis Lazuli [Hydrous phosphate of magnesium, iron, aluminum]
  1. Azure to green
  2. # 5-6; Monoclinic, twinned, pleochroic
  3. Ornamental stone, gems, beads
• Malachite [Hydrous carbonate of copper]
  1. Green
  2. # 3.5-4; Monoclinic
  3. Source of copper; paint pigment, decorative stones, beads
• Opal [Hydrated silicon dioxide]
  1. Red, orange, brown, multicoloured
  2. # 5.5-6.5; Amorphous, opalescent, fluorescent
  3. Jewelry
• Pearl [Organic]
  1. White, red, black, with tints
  2. # 3-4; (crystals n/a)
  3. Beads
• Pistacite (See: Epidote)
• Prehnite [Hydrous silicate of calcium, aluminum]
  1. Pale green, grey, yellow, white
  2. # 6.6-5; Orthorhombic, chatoyant, pleochroic
  3. Ornamental stone, gems
• Pyrite [Sulfide of iron]
  1. Yellow
  2. # 6-6.5; Cubic, octohedral, dodecahedral
  3. Mined for sulfur in the past
• Quartz [Silicon dioxide]
  1. Apple green (chrysoprase), Brown to grey (smoky quartz), Clear (rock crystal), Pink (rose quartz), Purple (amethyst), Reddish brown (jasper, plasma), Reddish orange (carnelian), Various colours (agate, chalcedony, onyx, sardonyx)
  2. # 6.5-7; Trigonal, twinned
  3. Glass, electrical components, optical lenses, abrasives, building stones, ornamental stones
• Rhodochrosite [Carbonate of manganese]
  1. Dark red to brown
  2. # 4; Trigonal
  3. Ornamental stone, trinket boxes, mosaics, pots, cameo brooches, beads
• Rhodonite [Silicate of manganese]
  1. Bright pink to red
  2. # 5.5-6.5; Triclinic
  3. Brooches, beads
• Ruby [Oxide of aluminum, with chromium, iron]
  1. Red
  2. # 9; Trigonal, asterism
  3. Gems
• Rutile [Oxide of titanium]
  1. Red
  2. # 6-6.5; Tetragonal, asterism
  3. Ore of titanium; gems
• Sapphire [Oxide of aluminum, with titanium, iron]
  1. Blue, orange-pink, golden, white, black
  2. # 9; Trigonal, asterism
  3. Jewelry, ornaments; mechanisms in clocks, watches, meters; windows of furnaces; ballpoint pens
• Scapolite [Solid solution between marialite and meionite]
  1. Colourless, white, yellow, grey, pink, violet
  2. # 5-5.5; Tetragonal
  3. Research, collections, gems
• Sodalite [Chlorosilicate of sodium, aluminum]
  1. Dark blue
  2. # 5-5.5; Cubic
  3. Jewelry, ornamental stones
• Sphene or Titanite [Silicate of calcium, titanium]
  1. Various colours
  2. # 5-5.5; Monoclinic, twinned
  3. Source of titanium oxide; gems
• Spinel [Oxide of magnesium, aluminum]
  1. Red, green, black, blue, brown
  2. # 8; Cubic, asterism
• Spodumene [Silicate of lithium, aluminum]
  1. Green/yellow-green (hiddenite), Violet (kunzite)
  2. # 6-7; Monoclinic, twinned
  3. Source of lithium; gems
• Titanite (See: Sphene)
• Topaz [Hydrous fluorosilicate of aluminum]
  1. Colourless, pale yellow, pale blue, green, pink
  2. # 8; Orthorhombic, hard
  3. Jewelry
• Tourmaline [Hydrous fluroborosilicate of sodium, calcium, lithium, magnesium, aluminum, ferric and ferrous iron]
  1. White, blue, green, brown
  2. # 7-7.5; Trigonal, pleochroic
  3. Gems, display
• Tourquoise [Hydrous hydrated phosphate of copper]
  1. Blue to green
  2. # 5-6; Triclinic, brittle, porous
  3. Gems
• Tufa (See: Aragonite)
• Vesuvianite or Idocrase [Hydrous silicate of calcium, magnesium, iron, aluminum]
  1. Dark green, brown, yellow
  2. # 6.5; Tetragonal, pleochroic
  3. Collections, gems
• Zircon [Silicate of zirconium]
  1. Blue, brown, green, orange, red, yellow
  2. # 6.5-7.5; Tetragonal, twinned, glassy
  3. Lining of furnaces, kilns; jewelry, ornamentation
• Zoisite [Hydrous silicate of calcium, aluminum]
  1. Colourless, pink, red, blue
  2. # 6.5-7; Orthorhombic, pleochroic
  3. Gems, beads

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