Gemstone Mining in the United States

A wide variety of gemstones are found throughout the United States

A Diversity of U.S. Gemstones

A surprising diversity of gemstones are produced within the United States. Did you know that Montana is the home of world-famous sapphire localities; and, that emeralds, rubies and sapphires are found in North Carolina? Have you ever seen an "Oregon sunstone" that flashes with a copper aventurescence or a cultured freshwater pearl with a golden luster produced in Tennessee? These are just a few of the unique gemstones produced in the United States.

The United States Geological Survey reports that notable quantities of gem-quality beryl, coral, garnet, feldspar, opal, quartz, sapphire, ruby, shell, pearls, peridot, topaz, tourmaline and turquoise are currently produced in the United States. The states with the highest dollar value of gemstone production are listed here in descending order: Arizona, North Carolina, Oregon, Utah, California, Tennessee, Montana, Arkansas, Colorado, Idaho, and Maine.

Small Mines and Recreational Miners

Although the United States produces a diversity of gemstone varieties the quantity produced is very small. In calendar year 2011 the total gemstone production of the United States was only $11 million. That amount is very very small compared to the $23.5 billion in gemstones that were imported. The United States has greater than a 99.9 percent dependence on foreign gemstone suppies.

Most of the gemstone production in the United States comes from very small mines with just two or three employees who are often part-time or seasonal workers. Very few of the mines have more than a dozen employees and operate during all four seasons of the year. In 2011 only about 1000 to 1200 people in the United States worked in the gemstone mining industry.

Did You Know? If you attend the Tucson Gem and Mineral Show (held every February) you can purchase rough or cut stones from most of the important gemstone mines in the United States - and often purchase directy from the person who did the mining. Don't be afraid to ask - they usually enjoy telling you all about their operation. Sometimes the same person mines, cuts and markets the stones!

Much of the gemstone mining in the United States is done by rockhounds (amateurs who search for rocks, minerals, gemstones and fossils as a hobby). Many of them do their rockhounding on public land (areas owned by the government where individuals can collect if they observe the rules). Others go to fee mining sites. These are proven gemstone deposits where visitors can pay a fee, look for gemstones and keep any that they find.

Why Is Production So Low?

Some of the gemstone deposits in the United States have been associated with major metal deposits which are much more valuable. The gemstone deposits, which are generally very slow to mine, were removed in a rush to get to the much more valuable minerals below. Other gemstone deposits are not operated because they are extremely labor intensive. They would be mined in countries where labor rates are very low - but they can not be operated at a profit at United States labor rates. Other deposits are not mined because environmental or safety concerns make mining unattractive.

Patronage for Domestic Gemstones

Many people really enjoy gemstones produced from domestic deposits. Some mineral collectors favor certain localities and some gemstone buyers (especially tourists) have a strong desire to purchase a "Montana Sapphire" or an "Oregon Sunstone" when they visit those states. This patronage strongly supports the price of stones from certain localities - far above the price of similar-size, similar-quality stones from anywhere else in the world. This patronage also supports a small domestic lapidary industry.

Many people who visit Arizona want to bring home a piece of petrified wood and many people who visit upstate New York want to find a "Herkimer Diamond". There is even one location in Arkansas, Crater of Diamonds, where anyone can become a diamond miner by paying a small fee. These are fun activities, many people enjoy them and they support the small gemstone industry of the United States.

A diversity of gemstones are produced from mines throughout the United States. Click on a gemstone in the photo above to learn more about it. Top row: malachite and azurite cabochon (Arizona), a rough ruby (North Carolina), a faceted orange sunstone (Oregon), a teardrop variscite cabochon (Utah). Second row: a vesuvianite cabochon (California), a freshwater cultured pearl (Tennessee), a cabochon of Montana Moss Agate (Montana), a handful of diamonds (Arkansas). Third row: two pieces of aquamarine rough (Colorado), an opal cabochon (Idaho), a faceted bicolor tourmaline (Maine), a faceted fire opal (Nevada).

U.S. Gemstone Production Values in Thousands of Dollars
Gem Material	2009	2010	2011
Beryl	918	1,700	1,740
Coral	150	150	150
Garnet	148	149	110
Gem Feldspar	858	693	756
Geode / Nodules	105	110	110
Opal	225	189	71
Quartz - Microcrystalline	231	273	333
Quartz - Cryptocrystalline	216	208	248
Sapphire / Ruby	256	344	343
Shell	713	821	832
Topaz	ND	ND	ND
Tourmaline	112	95	73
Turquoise	531	449	1330
Other	4,850	4,840	4,950
Totals	9,310	10,000	11,000
ND - value not disclosed because it would reveal proprietary information of a small number of producers - included in totals.

#1 ARIZONA
Arizona Gemstomes In 2011, the state of Arizona led the United States in the production of gemstones. Arizona has long been famous as a producer of turquoise, peridot and petrified wood. Gemstones such as azurite, chrysocolla and malachite are associated with the Arizona's many copper deposits and have a long history of being produced there. Agate, amethyst, garnet, jade, jasper, obsidian, onyx, and opal have all been found in Arizona and used to make gems. The photo at right shows several cabochons cut from Arizona copper minerals. They are an oval of chrysocola and malachite on the left; three triangular cabs of azurite and malachite; and, on the right a quartz cabochon with chrysocolla inclusions. All materials were found in the Morenci area, a famous copper locality.

#2 NORTH CAROLINA
North Carolina Gemstomes Most people are surprised to hear that rubies, sapphires and emeralds can be found in North Carolina. Although the area does not support a large gemstone mining and cutting industry there are many pay-to-prospect mines where anyone can enter, pay a small fee, and keep all of the gemstones that are found. Some local business have skilled gem cutters and bench jewelers who can turn a nice piece of rough that you find into a beautiful piece of jewelry. Gem materials found in North Carolina include: aquamarine, beryl, citrine, emerald, garnet, moonstone, rose quartz, ruby, sapphire, smokey quartz, staurolite, topaz, and tourmaline. There are even a few places where you can find gold. Photo of North Carolina rubies by Peter Cristofono.

#3 OREGON
Oregon Gemstomes Oregon produces some of the best gem-quality feldspars in the world. Several small mining operations have become world famous for producing "Oregon Sunstone", a transparent feldspar that is loaded with tiny copper platelets aligned in a common orientation. When a sunstone is played in the light, at just the right angle, these platelets simultaneously reflect a flash of light. Oregon produces several other gem materials including the famous "thunderegg", a geode that is ugly on the outside but often filled with beautiful chalcedonly, opal or crystals that can be cut into gemstones. Some people argue that thundereggs are more popular than sunstone! Oregon also produces a number of different fire opals and common opals with beautiful colors.

#4 UTAH
Utah Gemstomes Utah produces a wide variety of gemstones. The tear-drop shape variscite cabochon shown at right was cut from material found near Fairfield Utah. Although topaz is Utah's state gemstone, the gemstone that is getting a lot of recent attention is red beryl, also known as bixbyite. Amethyst, garnet, jasper, agate and opals are also found at numerous locations in Utah.

#5 CALIFORNIA
California Gemstomes California is widely known for its tourmaline and turquoise production. Native Americans were the first to treasure these minerals and a commercial gemstone industry was active by the late 1800s. The tourmaline deposits of Riverdale and San Diego Counties have supplied more tourmaline for cutting and mineral specimens than any other tourmaline deposits in the northern hemisphere. California gemstones also include: many varieties of agate, jasper, jade, garnet and quartz. The state is one of the only sources of benitoite, a blue barium titanium silicate, that has been named the state gemstone. The image at right is a Vesuvianite cabochon cut from material produced at the Happy Camp mine in Siskiyou County.

#6 TENNESSEE
Tennessee Gemstomes Tennessee is well known for a single gem material - pearls. The American Pearl Company operates the only freshwater pearl farm in the United States. They produce cultured freshwater pearls from native river mussels. The coin-shaped pearls in the image at right are from the American Pearl Company and display irridescent shades of golden, pink and blue.

#7 MONTANA
Montana Gemstomes Montana's most popular gemstone product is sapphire. Yogo Gulch sapphires have been famous for over 100 years and the production of sapphire continues today. Sapphires are produced from both rock and alluvial deposits. They occur in a wide range of colors which include: blue, blue-green, green, pink, pale red, purple, yellow and orange. Many people enjoy visiting pay-to-dig mines in Montana to look for sapphires. Some gem-grade garnets are also produced from the alluvial deposits. Rockhounds in many parts of Montana enjoy looking for agate and jasper. One of the most popular is "Montana Moss Agate", a transparent to translucient material that usually has brown to black bands or moss in a wide variety of patterns. Cabochons cut from Montana Moss Agate are shown at right.

#8 ARKANSAS
Arkansas Gemstomes The most popular gemstone locality in Arkansas is Crater of Diamonds, where anyone can pay a fee, look for diamonds, and keep any that are found. The site is an operating state park and visitors usually find hundreds of carats of diamonds every year. Arkansas's most important gem material is quartz. In Arkansas, clear quartz is often called "rock crystal". It is produced and sold as specimens and also used for faceted stones, beads, carvings, spheres and decorative items. Exceptional specimens of rock crystal can sell for thousands of dollars. Clear, undamaged single crystals are made into pendants, earrings and other types of jewelry. In addition to rock crystal, Arkansas produces other quartz gems including agate, chert, jasper, opal, petrified wood and smoky quartz (frequently heat-treated rock crystal).

#9 COLORADO
Colorado Gemstomes Many different gemstones are produced in Colorado. These include: aquamarine, amazonite, garnet, topaz, tourmaline, lapis lazuli, quartz, smoky quartz, rose quartz, amethyst, turquoise, peridot, sapphire, zircon, agate and jasper. A rough diamond from Colorado was cut into a 16.87 carat stone. It is the largest cut diamond ever produced from United States rough. Aquamarine is the state gemstone of Colorado and it is mostly found at high elevations on Antero Mountain. The three crystals of Antero Mountain aquamarine shown at right were photographed by Susan Amador.

#10 IDAHO
Idaho Gemstomes Idaho produces relatively small quantities of many different gemstones. Agates and jaspers are produced from deposits scattered across the state. Red facet-grade and star almandite garnet is produced from alluvial deposits at a number of locations. Beautiful fire, precious and common opals are produced at many locations in Idaho. The opal shown at right was produced from the Constellation Mine near the community of Spencer.

#11 MAINE
Maine Gemstomes The first commercial gemstone mine in the United States that was operated by miners who were not Native Americans was at Mount Mica, Maine. There a large deposit of tourmaline was discovered by children in 1820. Two years later a mine was opened and it yielded thousands of carats of gem-quality tourmaline crystals. Since then the pegmatite deposits of western Maine have produced many varieties of tourmaline, aquamarine, morganite, smoky quartz, rose quartz and amethyst. The three stones in the photo at right are very nice tourmalines from the Dunton Quarry, located in Oxford County. Photo by Thuss Photography, used with permission of the Maine State Museum.

NEVADA (unranked)
Nevada Gemstomes A variety of gemstones have been found in Nevada and the state is well known for its opal. After Australia, some of the finest black opals in the world come from Virgin Valley, Nevada. The specimen at right is a 9 millemeter faceted yellow fire opal of about 1.79 carats cut from rough produced in Nevada. The state is also well known for its turquoise, petrified wood, agate, jasper and obsidian.