Home » Gemstones
Ruby and Sapphire
Ruby and Sapphire are the 2nd and 3rd most popular colored stones in the United States.
Gifts that Rock! Find something for the rockhound on your holiday shopping list.
100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.
All About Diamonds
Diamond A collection of photos, articles, facts, maps and graphs about diamonds.
Amethyst - the most popular purple gem. It has a beautiful color and reasonable price.
Topaz is a popular birthstone and the #8 mineral in the Mohs Hardness Scale.
Pictures of Opal A collection of different types of opal from all around the world and Mars too!
Emerald is the most popular green gemstone in the United States and most of the world.
Don*t Go To Jail
Mineral collectors must know the rules for removing specimens from public and private property.
Green Gemstones - emerald, peridot, jade, tsavorite, chrome diopside, chrysoprase, more.
Gems from Space
Extraterrestrial Gems A number of materials from space are used as attractive gems.
Turquoise A blue to bluish- green gem material that has been used for over 6000 years.
United States Gemstones Small mines in the U.S. produce a diversity of gemstones.
Tanzanite was unknown until a few decades ago but it has erupted into wide popularity.
Tumbled Stones are rocks that have been rounded, smoothed and polished in a rock tumbler.
Garnet is best known as a red gemstone. It occurs in any color and has many industrial uses.
Blood Diamonds Illegally-traded diamonds that may have been stolen or used to fund conflict.
Strontium Titanate - lab created diamond simulant with fire much stronger than diamond.
Blue Gemstones - Most people shopping for a colored stone are looking for something blue.
Ethiopian Opal - The new opal heavyweight that might give Australia a run.
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!
Sunstone A feldspar with aventurescence caused by tiny copper inclusions.
Peridot is the gem variety of olivine. Derived from the mantle and rarely from meteorites.
Organic Gems are gems formed from plant or animal materials.
Gem Mineral Collections are a great way to learn about gem materials. Get yours.
Ant Hill Garnets
Ant Hill Garnets - tiny gems that ants haul to the surface and discard on their anthill. Honest!
Ammolite is a fossil and a gemstone. It is shell material from fossil ammonites.
Lapis Lazuli - a metamorphic rock and the most popular blue opaque gemstone in history.
Tourmaline - the most colorful mineral and natural gem material on Earth.
Zircon is a popular and colorful gem with fire and brightness that rivals diamond.
Rose Quartz is the name used for specimens of translucent quartz with a pink color.
Ruby and Sapphire
Ruby & Sapphire are gem corundums - ruby when red, sapphire when other colors.
Fire Opal is a transparent to translucent opal with a yellow, orange or red background color.
Beryl - the mineral of emerald, aquamarine, morganite, heliodor, goshenite, and more.
Gemstones of the World : A book by Robert Schumann. Over one million copies sold.
US Diamond Mines
US Diamond Mines Where are diamonds mined in the United States?
Spodumene is an ore of lithium and the mineral of the gems kunzite and hiddenite.
What Is Jade?
Jade has been used as a gemstone and a tool-making material for for 1000s of years.
Star Garnets are found in only a few locations worldwide. They are the state gems of Idaho.
Amazing Agate Photos
Beautiful Agates A gallery of spectacular agate photos and descriptions by Richard Weston.
Jet is a black organic gem material that forms from well-preserved woody material.
Petrified Wood is a fossilized wood that often serves as a colorful gem material.
You Can Be A Diamond Miner! At the Crater of Diamonds mine you can keep what you find.
Red Beryl is one of the rarest gems. Small amounts are mined at one locality in Utah.
Gem Silica is a blue chalcedony colored by copper. It is the rarest and most valuable chalcedony.
Spinel The gemstone that was confused with ruby and sapphire for over 1000 years.
Cabochons A photo gallery of cabochon gemstones from around the world.
Malachite has served as a gem material, pigment and ore of copper for thousands of years.
Ametrine is a bicolor quartz (amethyst + citrine) and a gemstone of growing popularity.
Diamonds Do Not Form From Coal Learn several reasons why the coal origin is false.
Facts About Diamonds
Facts About Diamonds You are a diamond expert if you know all of these!
Bloodstone is a dark green jasper with a splatter of red color that looks like blood.
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.
Zoisite is a diverse gem. Tanzanite, thulite and anyolite are three of its gem varieties.
US Gem Production
U.S. Gemstone Production is very low compared to the U.S. being the largest consumer.
Rhodochrosite : a manganese mineral used as an ore, a pink gem and an ornamental stone.
Geology of Gems
Geology of Gems - The first comprehensive book on the geology of gem deposits.
Kyanite is a metamorphic mineral used to make porcelain, abrasive products and gems.
Apatite produces gemstones with vivid colors and is popular with collectors.
Rock Tumblers - All about rock tumblers and rock tumbling. Read before you buy a tumbler.
Smoky Quartz - A brown color-variety of the mineral quartz often cut as a gem.
Iolite is the gem variety of the mineral cordierite. An alternative to sapphire and tanzanite.
Aventurine - a translucent quartz with reflective inclusions that cause aventurescence.
Brown Diamonds are growing in popularity and are frequently seen in fashion jewelry.
Azurite is a vivid blue copper mineral that can be cut into beautiful cabochon gems.
Synthetic Diamonds of spectacular quality are now being produced in labs.
Titanite aka Sphene
Titanite is also known as sphene. It is a minor source of titanium and a minor gem.
Chrome Diopside is a green gemstone that is often used as an alternative stone for emerald.
Chatoyant Gems look like the eye of a cat. They have a line of light that moves across the gem.
Benitoite - Geology of the State Gem of California - USGS report from 1911.
Moldavite is a gem material born about 15 million years ago when a pair of asteroids struck Europe.
Rhodonite is a pink manganese silicate used as a gemstone, an ornamental stone and an ore.
Diamonds are mined in many countries and their relative importance changes frequently.
Polka Dot Agate
Polka Dot Agate - a translucent blue to white agate with a suspension of colorful dots.
Scapolite can be a pretty faceted stone or a translucent cab with cats-eye effects.
Peanut Wood? Yes! It is a very interesting gem material found in Western Australia.
Heliodor is a yellow, greenish-yellow or golden yellow beryl used as a gem.
Chrysoprase - The translucent green variety of chalcedony that is colored by nickel.
50+ Different Tumbled Stones for sale at RockTumbler.com. (affiliated with geology.com)
Helenite is a man-made glass produced by fusing ash from the 1980 Mount St. Helens eruption.
Andalusite - exhibits strong pleochroism and often has sets of oriented inclusions.
Chrysoberyl an extreme gem. Its hardness is 8.5, can display chatoyance or color-change.
Iris Agate can produce a rainbow of colors when light passes between its thin bands.
Unakite A gem material composed of green epidote and pink orthoclase.
Azurmalachite is a mixture of malachite and azurite. It can be a beautiful blue and green gem.
Serpentine - a group of metamorphic minerals used as gems and architectural stone.
Canadian Diamond Mines produce some of the largest and highest quality diamonds!
Hardness Picks - Mohs hardness testing with precise and easy-to-use hardness picks.
Turritella Agate is a brown agate containing snail fossils from the Green River Formation.
Geology Tools - Rock hammers, field bags, hand lenses, maps, hardness picks, gold pans.
Petrified Palm is often confused with petrified wood. It is a distinctly different material.
Maw Sit Sit
Maw Sit Sit is a metamorphic rock and a gem material that was once thought be jade.
Prasiolite is amethyst that has been heat-treated to a leek-green color.
K2 Granite is a white granite with blue orbs of azurite. It is a new gem material from Pakistan.
Semiprecious vs. Precious - What is the difference between these two types of stones?
Fee Mining sites are mines that you can enter, pay a fee, and keep anything that you find.