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