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Common Gemstone Groups, Species and Varieties

by Doreen, Expert Gemologist
Exclusively for Fire Mountain Gems and Beads®

See how different gemstones are interrelated or grouped, and discover common trade names for many of them.

Group Species Mohs Hardness Variety/Trade Names
  Actinolite 5 - 6 Cat's eye
Alabaster 2 - 2-1/2 Satinspar (fibrous gypsum, often chatoyant), selenite
Amber 2 - 2-1/2 Amber (baltic, dominican, etc.)
Ammonite Variable Ammolite, korite, calcentine (name for iridescent Canadian material)
Andalusite 7 - 7-1/2 Chiastolite, viridine
Apatite 5 Cat's eye apatite, asparagus stone (green), teal, green and other colors
Aragonite 3-1/2 - 4 By color (yellow, brown, white, gray, green, blue, other colors)
Azurite 3-1/2 - 4 Chessy copper, azure stone
Azurmalachite 3-1/2 - 4 Rock composed of azurite and malachite
Beryl 7-1/2 - 8 Emerald, aquamarine, goshenite, bixbite, heliodor, morganite, maxixe beryl
Calcite 3 Iceland spar, marble, onyx marble, satinspar (fibrous aggregate, often chatoyant--the name is also used for a similar variety of gypsum)
Chalcedony 6-1/2 - 7 Milky chalcedony, chrysoprase, carnelian, bloodstone (heliotrope), agate, moss agate, onyx, jasper, fire agate, dendritic agate, petrified wood, agatized wood
Charoite 5 - 6 None
Chrysoberyl 8-1/2 Alexandrite, cat's eye alexandrite, cat's eye (semi transparent-semitranslucent yellow-yellowish green, grayish green, brown to brownish yellow)
Coral (organic material) 3-1/2 - 4 Different colors
Corundum 9 Ruby, star ruby, sapphire (different colors), star sapphire (different colors)
Diamond 10 Colorless--fancy colors
Diopside 5-1/2 - 6 Star diopside, cat's eye diopside, chrome diopside, malacolie, alalite, violane
Feldspar Microline feldspar 6 - 6-1/2 Amazonite (or Amazon stone)
Orthoclase feldspar 6 - 6-1/2 Moonstone (different colors)
Plagioclase feldspar 6 - 6-1/2 Labradorite (different colors), sunstone, rainbow moonstone is a trade name for transparent-semitranslucent white-grayish labradorite with multicolored labradorescence)
  Fluorite 4 Multicolored, blue John (bluish violet to purple on a reddish to colorless background)
Garnet Almandite garnet 7 - 7-1/2 Reddish orange to red, star almandite
Andradite garnet 6-1/2 - 7 Demantoid, melanite, topazolite
Grossularite garnet 7 - 7-1/2 Hessonite, tsavorite
Pyrope garnet 7 - 7-1/2 Medium to dark reddish garnet
Rhodolite garnet 7 - 7-1/2 Transparent, purplish red through reddish purple
Spessarite garnet 7 - 7-1/2 Transparent yellowish orange to reddish orange
Color change garnets 7 - 7-1/2 Malaia (light to dark--pinkish orange, reddish orange, yellowish orange)
  Natural glass 5 - 5-1/2 Moldavite, obsidian (sheen, snowflake, rainbow), tektites
Hematite 5-1/2 - 6-1/2 None
Hemimorphite 4-1/2 - 5 None
Howlite 3 - 3-1/2 None
Idocrase (also known as vesuvianite) 6-1/2 Californite, xanthite, cyprine
Iolite 7 - 7-1/2 Dichroite, bloodshot iolite
Jadeite Jade 6-1/2 - 7 Imperial jade, yunnan jade, moss in snow
Nephrite Jade 6 - 6-1/2 Depending on color--mutton fat, tomb jade, chicken bone, spinach jade
Kyanite 4 - 7-1/2 None
Lapis Lazuli 5 - 6 Depending on color/mine--Persian or Afghan, Russian, Chilean
Malachite 3-1/2 - 4 Also known as peacock stone
Opal 5 - 6-1/2 White opal, black opal, fire opal, boulder opal, common opal, milky opal, onyx opal, wax opal, moss opal, etc.
Pearl 2-1/2 - 4 Natural, freshwater pearl (multiple colors)
Pectolite 4-1/2 - 5 Larimar
Peridot 6-1/2 - 7 Chrysolite (used primarily in Europe)
Pyrite 6 - 6-1/2 None
Quartz 7 Amethyst, citrine, tigereye, rock crystal, smoky quartz, rose quartz, aventurine quartz, rainbow or iris quartz, rutilated quartz, sagenitic quartz, dumortierite quartz, milky quartz, green quartz, quartzite, tourmalinated quartz, etc.
Rhodochrosite 3-1/2 - 4-1/2 None
Rhodonite 5-1/2 - 6-1/2 None
Serpentine 2-1/2 - 6 Bowenite, williamsite, verd antique
Shell 3-1/2 Mother-of-pearl shell, helmut shell, etc.
Sodalite 5 - 6 Sometimes called as Canadian blue stone, hackmanite (pink--fades rapidly)
Spinel 8 Multicolored, flame spinel 9 (orange-red), color change spinel, star spinel, ceylonite (black)
Spodumene 6-1/2 - 7 Kunzite, hiddenite, triphane
Sugilite 6-1/2 - 7-1/2 Royal azel, royal lavulite
Topaz 8 Sherry topaz, london topaz, imperial topaz, etc.
Tourmaline 7 - 7-1/2 Rubellite, dravite, verdelite, parti-colored, chrome tourmaline, multicolored, black tourmaline (or schorl)
Turquoise 5 - 6 Depending on color, mine source--Persian, American or Mexian, Sleeping Beauty, spiderweb, etc.
Unakite 6 - 7 None
Zircon 6 - 7-1/2 Colorless to multicolored
Zoisite 6 - 7 Tanzanite, ruby in zoisite, thulite

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