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Gemstones


Author: , PhD, GIA Graduate Gemologist


Gemstone Menu

Amazonite
Amethyst
Ametrine
Ammolite
Andalusite
Anyolite
Apatite
Aquamarine
Aventurine
Azurite
Azurmalachite
Beryl
  - Aquamarine
  - Emerald
  - Goshenite
  - Green Beryl
  - Heliodor
  - Morganite
  - Red Beryl
Benitoite
Birthstones
Bloodstone
Charoite
Chrysoberyl
Chrysoprase
Citrine
Cordierite
Diamond
  - Blue Diamonds
  - Brown Diamonds
  - Colored Diamonds
  - Green Diamonds
  - Red Diamonds
  - Yellow Diamonds
Dinosaur Bone
Diopside
Dryhead Agate
Emerald
Fire Agate
Fluorite
Gaspeite
Garnet
Gem Silica
Geodes
Goldstone
Goshenite
Green Beryl
Helenite
Heliodor
Hematite
Idocrase
Iolite
Iris Agate
Jade
Jadeite
Jet
K2 Granite
Kyanite
Labradorite
Lapis Lazuli
Lepidolite
Malachite
Maw Sit Sit
Moldavite
Moonstone
Morganite
Nephrite
Opal
  - Boulder Opal
  - Cat's-Eye Opal
  - Common Opal
  - Ethiopian Opal
  - Fire Opal
  - Imitation Opal
  - Matrix Opal
  - Morado Opal
  - Opalized Wood
  - Opalite
  - Precious Opal
  - Synthetic Opal
Organic Gems
Palm Wood
Peanut Wood
Peridot
Petrified Wood
Pinolith
Polka Dot Agate
Prasiolite
Quartz
  - Amethyst
  - Ametrine
  - Aventurine
  - Citrine
  - Prasiolite
  - Rose Quartz
  - Smoky Quartz
Red Beryl
Rhodochrosite
Rhodonite
Rose Quartz
Ruby
Sapphire
  - Fancy Sapphire
Scapolite
Serpentine
Smithsonite
Smoky Quartz
Sodalite
Sonora Sunrise
Sphalerite
Sphene
Spinel
Spodumene
Strontium Titanate
Sugilite
Sunstone
Tanzanite
Tiger's-Eye
Tiffany Stone
Titanite
Topaz
  - Blue Topaz
Tourmaline
Turquoise
Turritella Agate
Unakite
Variscite
Vesuvianite
Wonderstone
Zircon
Zoisite

Birthstones
birthstones
Birthstones are gems assigned to the month of a person*s birth. They are popular gifts in the U.S.
Andalusite
andalusite
Andalusite is a metamorphic mineral and a strongly pleochroic gem material.
100+ Gems
gem photos
100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.
All About Diamonds
Diamond
Diamond A collection of photos, articles, facts, maps and graphs about diamonds.
Tumbled Stones
Tumbled Stones
Tumbled Stones are rocks that have been rounded, smoothed and polished in a rock tumbler.
Spinel
Spinel
10 Gemmy Facts About Spinel - Is spinel the world*s most overlooked gem?
Blue Gemstones
blue gemstones
Blue Gemstones - Most people shopping for a colored stone are looking for something blue.
Green Gemstones
Green Gemstones
Green Gemstones - emerald, peridot, jade, tsavorite, chrome diopside, chrysoprase, more.
Opal Photos
Opal
Pictures of Opal A collection of different types of opal from all around the world and Mars too!
Gem Minerals
Gem Mineral Collections
Gem Mineral Collections are a great way to learn about gem materials. Get yours.
Geology of Gems
Geology of Gems
Geology of Gems - The first comprehensive book on the geology of gem deposits.
Moonstone
moonstone
Moonstone is one of the world*s most popular gems. A soft glow of light floats under its surface.
Ruby and Sapphire
Ruby and Sapphire
Ruby and Sapphire are the 2nd and 3rd most popular colored stones in the United States.
Geodes
Geodes
Geodes look like ordinary rocks on the outside but can be spectacular inside!
Gemstone Book
Gemstones of the World
Gemstones of the World : A book by Robert Schumann. Over one million copies sold.
Emerald
emerald
Emerald is the most popular green gemstone in the United States and most of the world.
Blood Diamonds
Blood Diamonds
Blood Diamonds Illegally-traded diamonds that may have been stolen or used to fund conflict.
Morganite
morganite
Morganite is an orange to pink gemstone, a variety of beryl, that is growing rapidly in popularity.
American Gemstones
U.S. Gemstones
Mined in America - Small mines in the United States produce a diversity of beautiful gemstones.
Gems from Space
Gems from Space
Extraterrestrial Gems A number of materials from space are used as attractive gems.
Amethyst
Amethyst
Amethyst - the most popular purple gem. It has a beautiful color and reasonable price.
Cat*s Eye Gems
cats eye gems
Cat*s Eye Gems look like the eye of a cat. They have a line of light that moves across the gem.
Hardness Picks
Hardness Picks
Hardness Picks - Mohs hardness testing with precise and easy-to-use hardness picks.
Goldstone
goldstone
Goldstone is a colorful man-made glass that is full of highly-reflective metallic inclusions.
Turquoise
Turquoise
Turquoise A blue to bluish- green gem material that has been used for over 6000 years.
Spodumene
Spodumene
Spodumene is an ore of lithium and the mineral of the gems kunzite and hiddenite.
Ant Hill Garnets
Ant Hill Garnets
Ant Hill Garnets - tiny gems that ants haul to the surface and discard on their anthill. Honest!
Strontium Titanate
strontium titanate
Strontium Titanate - lab created diamond simulant with fire much stronger than diamond.
US Diamond Mines
United States Diamond Mines
US Diamond Mines Where are diamonds mined in the United States?
Labradorite
Labradorite
Labradorite is a feldspar gem that can produce bright flashes of iridescent color.
Ruby and Sapphire
Ruby and Sapphire
Ruby & Sapphire are gem corundums - ruby when red, sapphire when other colors.
Biggest Misconception
Diamonds from Coal
Diamonds Do Not Form From Coal Learn several reasons why the coal origin is false.
Garnet
Garnet
Garnet is best known as a red gemstone. It occurs in any color and has many industrial uses.
What Is Jade?
Jade
Jade has been used as a gemstone and a tool-making material for for 1000s of years.
Arkansas Diamonds
Arkansas Diamonds
You Can Be A Diamond Miner! At the Crater of Diamonds mine you can keep what you find.
Topaz
Topaz
Topaz is a popular birthstone and the #8 mineral in the Mohs Hardness Scale.
Petrified Wood
Petrified Wood
Petrified Wood is a fossilized wood that often serves as a colorful gem material.
Fire Agate
Fire Agate
Fire Agate is a rare brown agate that exhibits iridescent colors of red, orange, yellow and green.
Tourmaline
Tourmaline
Tourmaline - the most colorful mineral and natural gem material on Earth.
Geology Tools
Geology Tools
Geology Tools - Rock hammers, field bags, hand lenses, maps, hardness picks, gold pans.
Ethiopian Opal
Ethiopian opal
Ethiopian Opal - The new opal heavyweight that might give Australia a run.
Azurmalachite
azurmalachite
Azurmalachite is a mixture of malachite and azurite. It can be a beautiful blue and green gem.
Organic Gems
Organic Gems
Organic Gems are gems formed from plant or animal materials.
Rock Tumbling
rock tumblers
Rock Tumblers - All about rock tumblers and rock tumbling. Read before you buy a tumbler.
Red Beryl
Red Beryl
Red Beryl is one of the rarest gems. Small amounts are mined at one locality in Utah.
Lab-Grown Diamonds
Lab-Grown Diamonds
Lab-Grown Diamonds What are they? Can people really make diamonds? Are they real?
Yellow Diamonds
Yellow Diamonds
Yellow Diamonds are the most valuable yellow gems and the 2nd most common fancy diamond.
Ammolite
Ammolite
Ammolite is a fossil and a gemstone. It is shell material from fossil ammonites.
Citrine
citrine
Citrine is the transparent variety of quartz with a yellow to orange to reddish color.
Facts About Diamonds
Diamond Facts
Facts About Diamonds You are a diamond expert if you know all of these!
Tanzanite
tanzanite
Tanzanite was unknown until a few decades ago but it has erupted into wide popularity.
Goshenite
goshenite
Goshenite is the colorless variety of the mineral beryl and a gem of interest mainly to collectors.
Bloodstone
bloodstone
Bloodstone is a dark green jasper with a splatter of red color that looks like blood.
Opalite
Opalite
Opalite is a word that can refer to either common opal or a man-made opalescent material.
Aquamarine
Aquamarine
Aquamarine is a popular blue gemstone that serves as a birthstone for the month of March.
Malachite
Malachite
Malachite has served as a gem material, pigment and ore of copper for thousands of years.
Lapis Lazuli
lapis lazuli
Lapis Lazuli - a metamorphic rock and the most popular blue opaque gemstone in history.
Colored Diamonds
colored diamonds
Colored Diamonds are diamonds with a noticeable body color. They can sell for over $1M/carat.
Incorrect Names
incorrect gemstone names
Green Amethyst and Yellow Emerald are misleading names according to the FTC.
Magnesite
magnesite
Magnesite is a white mineral that is often dyed to imitate turquoise or dyed outrageous colors for fun.
Petrified Palm
Petrified Palm
Petrified Palm is often confused with petrified wood. It is a distinctly different material.
Kyanite
kyanite
Kyanite is a metamorphic mineral used to make porcelain, abrasive products and gems.
Green Diamonds
Green Diamonds
Green Diamonds - one of the rarest and most valuable diamond colors.
Cat's-Eye Opal
Cat's-Eye Opal
Cat's-Eye Opal - a phenomenal opal that exhibits chatoyance when properly cut en cabochon.
Jet
jet
Jet is a black organic gem material that forms from well-preserved woody material.
Cabochons
Cabochons
Cabochons A photo gallery of cabochon gemstones from around the world.
Rhodochrosite
Rhodochrosite
Rhodochrosite : a manganese mineral used as an ore, a pink gem and an ornamental stone.
Moldavite
moldavite
Moldavite is a gem material born about 15 million years ago when a pair of asteroids struck Europe.
Benitoite
Benitoite
Benitoite - Geology of the State Gem of California - USGS report from 1911.
Fire Opal
Fire Opal
Fire Opal is a transparent to translucent opal with a yellow, orange or red background color.
Smithsonite
Smithsonite
Smithsonite is a zinc carbonate mineral, an ore of zinc, and a minor gemstone.
Turritella Agate
Turritella Agate
Turritella Agate is a brown agate containing snail fossils from the Green River Formation.
Synthetic Opal
synthetic opal
Synthetic Opal is a man-made material with the play-of-color and appearance of natural opal.
Zircon
Zircon
Zircon is a popular and colorful gem with fire and brightness that rivals diamond.
Unakite
Unakite
Unakite A gem material composed of green epidote and pink orthoclase.
Helenite
Helenite
Helenite is a man-made glass produced by fusing ash from the 1980 Mount St. Helens eruption.
Common Opal
Common Opal
Common Opal is a material that does not exhibit the play-of-color seen in precious opal.
Opalized Wood
Opalized Wood
Opalized Wood is a gem material consisting of wood that has been replaced by opaline silica.
US Gem Production
US Gemstone Production
U.S. Gemstone Production is very low compared to the U.S. being the largest consumer.
Aventurine
Aventurine
Aventurine - a translucent quartz with reflective inclusions that cause aventurescence.
Gaspeite
gaspeite
Gaspeite is a rare green ore of nickel that has become a popular gem in southwestern jewelry.
Gem Beryl
Gem Beryl
Beryl - the mineral of emerald, aquamarine, morganite, heliodor, goshenite, and more.
Gemstone Microscopy
gemstone inclusions
Looking Into the Mysteries of Gems and exploring their hidden secrets with a microscope.
Variscite
Variscite
Variscite is a yellowish green to bluish green mineral. It is similar to turquoise and cut as a gem.
Tiffany Stone
Tiffany Stone
Tiffany Stone is a rare purple, blue and white rock, mined in Utah, and used as a gem.
Sonora Sunrise
Sonora Sunrise
Sonora Sunrise is a gem material of Mexico composed of red cuprite and blue-green chrysocolla.
Fancy Sapphire
Fancy Sapphires
Fancy Sapphires are gem corundums of any color other than red, blue or colorless.
Chrysoprase
Chrysoprase
Chrysoprase - The translucent green variety of chalcedony that is colored by nickel.
Diopside
Chrome Diopside
Chrome Diopside is a green gemstone that is often used as an alternative stone for emerald.
Star Garnet
Star Garnet
Star Garnets are found in only a few locations worldwide. They are the state gems of Idaho.
Zoisite
zoisite
Zoisite is a diverse gem. Tanzanite, thulite and anyolite are three of its gem varieties.
K2 Granite
K2 Granite - aka K2 Jasper
K2 Granite is a white granite with blue orbs of azurite. It is a new gem material from Pakistan.
Iolite
Iolite
Iolite is the gem variety of the mineral cordierite. An alternative to sapphire and tanzanite.
Titanite aka Sphene
Titanite
Titanite is also known as sphene. It is a minor source of titanium and a minor gem.
Canadian Diamonds
Canadian Diamonds
Canadian Diamond Mines produce some of the largest and highest quality diamonds!
Ametrine
Ametrine
Ametrine is a bicolor quartz (amethyst + citrine) and a gemstone of growing popularity.
Azurite
Azurite
Azurite is a vivid blue copper mineral that can be cut into beautiful cabochon gems.
Diamond Producers
Diamond Producers
Diamonds are mined in many countries and their relative importance changes frequently.
Blue Topaz
Blue Topaz
Blue Topaz - The most popular topaz for jewelry. The color is usually a product of treatment.
Peridot
Peridot
Peridot is the gem variety of olivine. Derived from the mantle and rarely from meteorites.
Scapolite
Scapolite
Scapolite can be a pretty faceted stone or a translucent cab with cats-eye effects.
Hemimorphite
Hemimorphite
Hemimorphite is an ore of zinc that can often be cut into gems with spectacular blue color.
Smoky Quartz
Smoky quartz
Smoky Quartz - A brown color-variety of the mineral quartz often cut as a gem.
Chrysoberyl
chrysoberyl
Chrysoberyl an extreme gem. Its hardness is 8.5, can display chatoyance or color-change.
Rose Quartz
Rose Quartz
Rose Quartz is the name used for specimens of translucent quartz with a pink color.
Heliodor
Heliodor
Heliodor is a yellow, greenish-yellow or golden yellow beryl used as a gem.
Polka Dot Agate
Polka Dot Agate
Polka Dot Agate - a translucent blue to white agate with a suspension of colorful dots.
Gem Silica
Gem Silica
Gem Silica is a blue chalcedony colored by copper. It is the rarest and most valuable chalcedony.
Brown Diamonds
Brown Diamonds
Brown Diamonds are growing in popularity and are frequently seen in fashion jewelry.
Sunstone
Sunstone
Sunstone A feldspar with aventurescence caused by tiny copper inclusions.
Serpentine
Serpentine
Serpentine - a group of metamorphic minerals used as gems and architectural stone.
Iris Agate
Iris Agate
Iris Agate can produce a rainbow of colors when light passes between its thin bands.
Lepidolite
Lepidolite
Lepidolite - a pink to purple mica sometimes used as a gem. A source of color in pink aventurine.
Imitation Opal
Imitation Opal
Imitation Opal is man-made and looks like opal, but without the same composition or structure.
Gifts That Rock
Gifts That Rock
Gifts That Rock - What are the most popular gift items in the Geology.com store
Charoite
Charoite
Charoite is a rare purple mineral from Russia used as a gem material and ornamental stone.
Rhodonite
rhodonite
Rhodonite is a pink manganese silicate used as a gemstone, an ornamental stone and an ore.
Sugilite
Sugilite
Sugilite is a rare mineral and a gemstone best known for its vibrant pink to purple color.
Maw Sit Sit
Maw Sit Sit
Maw Sit Sit is a metamorphic rock and a gem material that was once thought be jade.
Apatite
Apatite
Apatite produces gemstones with vivid colors and is popular with collectors.
Peanut Wood?
Peanut Wood
Peanut Wood? Yes! It is a very interesting gem material found in Western Australia.
Morado Opal
Morado Opal
Morado Opal is a purple variety of common opal which is found in central Mexico.
Prasiolite
Prasiolite
Prasiolite is amethyst that has been heat-treated to a leek-green color.