Gemstones

Diamond A collection of photos, articles, facts, maps and graphs about diamonds.

Bloodstone is a dark green jasper with a splatter of red color that looks like blood.

Blue Gemstones - Most people shopping for a colored stone are looking for something blue.

Tourmaline - the most colorful mineral and natural gem material on Earth.

Andalusite is a metamorphic mineral and a strongly pleochroic gem material.

Rock Tumblers - All about rock tumblers and rock tumbling. Read before you buy a tumbler.

Opalized Wood is a gem material consisting of wood that has been replaced by opaline silica.

100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.

Birthstones are gems assigned to the month of a person*s birth. They are popular gifts in the U.S.

Green Gemstones - emerald, peridot, jade, tsavorite, chrome diopside, chrysoprase, more.

Mined in America - Small mines in the United States produce a diversity of beautiful gemstones.

Ruby and Sapphire are the 2nd and 3rd most popular colored stones in the United States.

Ethiopian Opal - The new opal heavyweight that might give Australia a run.

Amethyst - the most popular purple gem. It has a beautiful color and reasonable price.

Tumbled Stones are rocks that have been rounded, smoothed and polished in a rock tumbler.

Gemstones of the World : A book by Robert Schumann. Over one million copies sold.

Extraterrestrial Gems A number of materials from space are used as attractive gems.

Moonstone is one of the world*s most popular gems. A soft glow of light floats under its surface.

Geology of Gems - The first comprehensive book on the geology of gem deposits.

Emerald is the most popular green gemstone in the United States and most of the world.

Pictures of Opal A collection of different types of opal from all around the world and Mars too!

Turquoise A blue to bluish- green gem material that has been used for over 6000 years.

Blood Diamonds Illegally-traded diamonds that may have been stolen or used to fund conflict.

Ammolite is a fossil and a gemstone. It is shell material from fossil ammonites.

Labradorite is a feldspar gem that can produce bright flashes of iridescent color.

Geodes look like ordinary rocks on the outside but can be spectacular inside!

Strawberry Quartz is a red to pink quartz with inclusions that look like strawberry seeds.

Peridot is the gem variety of olivine. Derived from the mantle and rarely from meteorites.

Gifts That Rock - What are the most popular gift items in the Geology.com store?

Topaz is a popular birthstone and the #8 mineral in the Mohs Hardness Scale.

Aquamarine is a popular blue gemstone that serves as a birthstone for the month of March.

Hardness Picks - Mohs hardness testing with precise and easy-to-use hardness picks.

Green Diamonds - one of the rarest and most valuable diamond colors.

13 Gemmy Facts About Spinel - Is spinel the world*s most overlooked gem?

Strontium Titanate - lab created diamond simulant with fire much stronger than diamond.

Jade has been used as a gemstone and a tool-making material for for 1000s of years.

Ruby & Sapphire are gem corundums - ruby when red, sapphire when other colors.

Common Opal is a material that does not exhibit the play-of-color seen in precious opal.

Goldstone is a colorful man-made glass that is full of highly-reflective metallic inclusions.

Cat*s Eye Gems look like the eye of a cat. They have a line of light that moves across the gem.

Spodumene is an ore of lithium and the mineral of the gems kunzite and hiddenite.

Petrified Wood is a fossilized wood that often serves as a colorful gem material.

Ant Hill Garnets - tiny gems that ants haul to the surface and discard on their anthill. Honest!

Diamonds Do Not Form From Coal Learn several reasons why the coal origin is false.

Citrine is the transparent variety of quartz with a yellow to orange to reddish color.

Cabochons A photo gallery of cabochon gemstones from around the world.

Tanzanite was unknown until a few decades ago but it has erupted into wide popularity.

Garnet is best known as a red gemstone. It occurs in any color and has many industrial uses.

Imitation Opal is man-made and looks like opal, but without the same composition or structure.

Benitoite - Geology of the State Gem of California - USGS report from 1911.

You Can Be A Diamond Miner! At the Crater of Diamonds mine you can keep what you find.

Star Garnets are found in only a few locations worldwide. They are the state gems of Idaho.

Gem Silica is a blue chalcedony colored by copper. It is the rarest and most valuable chalcedony.

Kyanite is a metamorphic mineral used to make porcelain, abrasive products and gems.

Lapis Lazuli - a metamorphic rock and the most popular blue opaque gemstone in history.

Gem Mineral Collections are a great way to learn about gem materials. Get yours.

Zircon is a popular and colorful gem with fire and brightness that rivals diamond.

Jet is a black organic gem material that forms from well-preserved woody material.

Fire Opal is a transparent to translucent opal with a yellow, orange or red background color.

Colored Diamonds are diamonds with a noticeable body color. They can sell for over $1M/carat.

Petrified Palm is often confused with petrified wood. It is a distinctly different material.

Opalite is a word that can refer to either common opal or a man-made opalescent material.

Yellow Diamonds are the most valuable yellow gems and the 2nd most common fancy diamond.

Morganite is an orange to pink gemstone, a variety of beryl, that is growing rapidly in popularity.

U.S. Gemstone Production is very low compared to the U.S. being the largest consumer.

Diamonds are mined in many countries and their relative importance changes frequently.

Organic Gems are gems formed from plant or animal materials.

Red Beryl is one of the rarest gems. Small amounts are mined at one locality in Utah.

Facts About Diamonds You are a diamond expert if you know all of these!

Aventurine - a translucent quartz with reflective inclusions that cause aventurescence.

Rhodochrosite : a manganese mineral used as an ore, a pink gem and an ornamental stone.

Goshenite is the colorless variety of the mineral beryl and a gem of interest mainly to collectors.

Fire Agate is a rare brown agate that exhibits iridescent colors of red, orange, yellow and green.

Magnesite is a white mineral that is often dyed to imitate turquoise or dyed outrageous colors for fun.

Morado Opal is a purple variety of common opal which is found in central Mexico.

US Diamond Mines Where are diamonds mined in the United States?

Blue Topaz - The most popular topaz for jewelry. The color is usually a product of treatment.

Azurite is a vivid blue copper mineral that can be cut into beautiful cabochon gems.

Charoite is a rare purple mineral from Russia used as a gem material and ornamental stone.

Sunstone A feldspar with aventurescence caused by tiny copper inclusions.

Green Amethyst and Yellow Emerald are misleading names according to the FTC.

Moldavite is a gem material born about 15 million years ago when a pair of asteroids struck Europe.

Malachite has served as a gem material, pigment and ore of copper for thousands of years.

Fancy Sapphires are gem corundums of any color other than red, blue or colorless.

Tiffany Stone is a rare purple, blue and white rock, mined in Utah, and used as a gem.

Lab-Grown Diamonds What are they? Can people really make diamonds? Are they real?

Helenite is a man-made glass produced by fusing ash from the 1980 Mount St. Helens eruption.

Unakite A gem material composed of green epidote and pink orthoclase.

Apatite produces gemstones with vivid colors and is popular with collectors.

Rose Quartz is the name used for specimens of translucent quartz with a pink color.

Looking Into the Mysteries of Gems and exploring their hidden secrets with a microscope.

Zoisite is a diverse gem. Tanzanite, thulite and anyolite are three of its gem varieties.

Chrysoprase - The translucent green variety of chalcedony that is colored by nickel.

Sugilite is a rare mineral and a gemstone best known for its vibrant pink to purple color.

Ametrine is a bicolor quartz (amethyst + citrine) and a gemstone of growing popularity.

Scapolite can be a pretty faceted stone or a translucent cab with cats-eye effects.

Smoky Quartz - A brown color-variety of the mineral quartz often cut as a gem.

Beryl - the mineral of emerald, aquamarine, morganite, heliodor, goshenite, and more.

Titanite is also known as sphene. It is a minor source of titanium and a minor gem.

Chrysoberyl an extreme gem. Its hardness is 8.5, can display chatoyance or color-change.

Hemimorphite is an ore of zinc that can often be cut into gems with spectacular blue color.

Chrome Diopside is a green gemstone that is often used as an alternative stone for emerald.

Serpentine - a group of metamorphic minerals used as gems and architectural stone.

Variscite is a yellowish green to bluish green mineral. It is similar to turquoise and cut as a gem.

Iris Agate can produce a rainbow of colors when light passes between its thin bands.

Canadian Diamond Mines produce some of the largest and highest quality diamonds!

Azurmalachite is a mixture of malachite and azurite. It can be a beautiful blue and green gem.

Iolite is the gem variety of the mineral cordierite. An alternative to sapphire and tanzanite.

Peanut Wood? Yes! It is a very interesting gem material found in Western Australia.

Brown Diamonds are growing in popularity and are frequently seen in fashion jewelry.

Maw Sit Sit is a metamorphic rock and a gem material that was once thought be jade.

Rhodonite is a pink manganese silicate used as a gemstone, an ornamental stone and an ore.

Lepidolite - a pink to purple mica sometimes used as a gem. A source of color in pink aventurine.

Geology Tools - Rock hammers, field bags, hand lenses, maps, hardness picks, gold pans.

Polka Dot Agate - a translucent blue to white agate with a suspension of colorful dots.

Cat's-Eye Opal - a phenomenal opal that exhibits chatoyance when properly cut en cabochon.

Heliodor is a yellow, greenish-yellow or golden yellow beryl used as a gem.

Prasiolite is amethyst that has been heat-treated to a leek-green color.

Smithsonite is a zinc carbonate mineral, an ore of zinc, and a minor gemstone.

K2 Granite is a white granite with blue orbs of azurite. It is a new gem material from Pakistan.

Gaspeite is a rare green ore of nickel that has become a popular gem in southwestern jewelry.

Synthetic Opal is a man-made material with the play-of-color and appearance of natural opal.

Turritella Agate is a brown agate containing snail fossils from the Green River Formation.

Sonora Sunrise is a gem material of Mexico composed of red cuprite and blue-green chrysocolla.