US Gemstone Mines: Arizona Oregon Idaho Montana Arkansas Nevada Home » Gemstones » Gemstone Mining in the United States Gemstone Mining in the United States A wide variety of gemstones are found throughout the United States U.S. Gemstones: A diversity of gemstones are produced from mines throughout the United States. 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). Scroll down to read more about these gems and others. 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 all 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. State Utah 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 , turquoise , and other gem materials are currently produced in the United States. Ten states with a long history and nice diversity of gemstone production include: Arizona , North Carolina , Oregon , California , Utah , Tennessee , Montana , Colorado , Arkansas , and Idaho . 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 directly 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! 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 supplies. 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. 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. U.S. Gemstone Production Values 11,300 9,570 ND - value not disclosed because it would reveal proprietary information of a small number of producers - included in totals. Data from USGS Minerals Yearbooks. 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 because the disruption that they cause is more costly than the value of the gem materials. 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 cannot 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. #1 ARIZONA Arizona Gemstones 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 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 here shows several cabochons cut from Arizona copper minerals. They are an oval of chrysocolla and malachite on the left; three triangular cabs of azurite and malachite in the center; and on the right, a quartz cabochon with chrysocolla inclusions. All materials were found in the Morenci area, a famous copper locality. Learn more about Arizona Gemstones . #2 NORTH CAROLINA North Carolina Gemstones 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 businesses 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, smoky quartz , staurolite , topaz , and tourmaline . There are even a few places where you can find gold . The North Carolina rubies in the photograph at right were captured by Peter Cristofono. Learn more about North Carolina Gemstones. #3 OREGON Oregon Gemstones 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 tilted 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 chalcedony, opal, or crystals inside.

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. There are several pay-to-dig sites in Oregon where you can find sunstone, opal, thundereggs and more. Learn more about Oregon Gemstones . #4 CALIFORNIA California Gemstones 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, and it 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.

There are several pay-to-dig sites in California where you can pay a fee, look for rocks, gold, minerals or gems and keep anything that you find. #5 UTAH Utah Gemstones Utah produces a wide variety of gemstones. Although topaz is Utah's state gemstone, the gemstone that is getting a lot of recent attention is red beryl , also known as bixbite. The faceted red beryl shown here from the Wah Wah Mountains is a beautiful example (photo by Bradley Payne of TheGemTrader.com ). Amethyst , garnet , jasper, agate, and opals are also found at numerous locations in the state. Utah also has the world's only locality where beautiful purple tiffany stone can be found. Learn more about Utah Gemstones . #6 TENNESSEE Tennessee Gemstones 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 photo are from the American Pearl Company and display iridescent shades of golden, pink, and blue. Learn more about Tennessee gemstones .

#7 MONTANA Montana Gemstones Montana's most popular gemstone product is sapphire . Yogo Gulch sapphires have been famous for over 100 years, and the production of sapphires in Montana 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 (colors often produced by heat treatment). 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 translucent material that usually has brown to black bands or "moss" in a wide variety of patterns. Learn more about Montana gemstones . #8 COLORADO Colorado Gemstones Many different gemstones are produced in Colorado.

These include aquamarine , amazonite, garnet , topaz , tourmaline , lapis lazuli , quartz , smoky quartz , rhodochrosite , 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. Rhodochrosite is the state mineral, and many specimens are cut into gemstones such as the stone at right from the Sweet Home Mine. Photo by Bradley Payne, TheGemTrader.com . If you visit Colorado, there are a few fee mining sites where you can pay a fee and look for gold or topaz, smoky quartz, and amazonite. Learn more about Colorado Gemstones . #9 ARKANSAS Arkansas Gemstones The most popular gemstone locality in Arkansas is Crater of Diamonds State Park , 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 small diamonds every year. There are several other fee mining areas in the state where you can pay a fee, look for minerals and keep what you find. 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). Learn more about Arkansas Gemstones . #10 IDAHO Idaho Gemstones Idaho's nickname is "The Gem State." It has a long history of producing a variety of gem materials . The most important gems produced to date have been star garnet and opal . Notable amounts of jade , topaz , zircon , and tourmaline have also been found in Idaho.

Agate, jasper, and petrified wood in many colors and patterns have been found and produced from small deposits throughout the state. Learn more about Idaho Gemstones . Maine (unranked) Maine Gemstones 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 are very nice tourmalines from the Dunton Quarry, located in Oxford County. Photo by Thuss Photography, used with permission of the Maine State Museum. Learn more about Maine Gemstones .

Louisiana (unranked) Louisiana Gemstones Most people would not think of Louisiana as a "gemstone state." However, it is the source of a unique variety of precious opal and a source for abundant amounts of " petrified palm wood ." The palm material found in the Catahoula Formation, a sedimentary rock unit deposited during Oligocene time, is so popular and well-known that the state legislature named it the official "state fossil." Learn more about Louisiana Gemstones . Nevada (unranked) Nevada Gemstones 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 shown here is a 9-millimeter 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 . There are three pay-to-dig opal mines in Nevada where you can pay a fee, look for opals and keep whatever you find.

Turquoise as a Mineral and Gemstone | Uses and Properties Turquoise Properties of a gemstone mineral that has been held in high regard for thousands of years. Turquoise and argillite inlay pieces: A collection of Ancestral Puebloan (Anasazi) turquoise and orange argillite inlay pieces from Chaco Canyon National Historical Park in New Mexico. These pieces date from about 1020-1140 CE and show the typical materials used in the ancient Chacoan bead and inlay industry. Public domain image from the National Park Service. What is Turquoise? Turquoise is an opaque mineral that occurs in beautiful hues of blue, blue-green, and yellow-green. It has been treasured as a gemstone for thousands of years. Isolated from one another, the ancient people of Africa, Asia, South America and North America independently made turquoise one of their preferred materials for producing gemstones, inlay, and small sculptures. Chemically, turquoise is a hydrous phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·5H2). Its only important use is in the manufacture of jewelry and ornamental objects.

However, in that use it is extremely popular - so popular that the English language uses the word "turquoise" as the name of a blue-green color that matches the stone. Very few minerals have a color that is so well known, so characteristic and impressive that the name of the mineral becomes so commonly used. Only three other minerals - gold , silver , and copper - have a color that is used in common language more than turquoise. Turquoise cabochons: A diverse collection of turquoise cabochons from various locations. From left to right in the upper row: a greenish blue turquoise cabochon with black matrix from China; a teardrop-shaped, slightly greenish blue turquoise cabochon from Arizona's Sleeping Beauty Mine; and, two sky-blue turquoise cabochons with chocolate brown matrix from the Altyn-Tyube Mine in Kazakhstan. In the center row: a small sky-blue turquoise cabochon from the Kingman Mines in Arizona; and, two small round sky-blue cabochons from the Sleeping Beauty Mine of Arizona.

In the bottom row: two small cabochons with black matrix from unknown mines in Nevada; a teardrop-shaped cabochon with slightly greenish blue turquoise in black matrix from the Newlanders Mine in Nevada; and, a rectangular cabochon of slightly greenish blue turquoise in reddish brown matrix from the #8 Mine in Nevada. Turquoise Colors Blue minerals are rare, and that is why turquoise captures attention in the gemstone market. The most desirable color of turquoise is a sky blue or robin's-egg blue. Some people inappropriately describe the color as "Persian blue" after the famous high-quality material mined in the area that is now known as Iraq. Using a geographic name with a gem material should only be done when the material was mined in that locality. After blue, blue-green stones are preferred, with yellowish green material being less desirable. Departure from a nice blue color is caused by small amounts of iron substituting for aluminum in the turquoise structure. The iron imparts a green tint to the turquoise in proportion to its abundance. Turquoise, especially the more porous varieties, can discolor with exposure to prolonged sunlight, heat, cosmetics, perspiration, and body oil.

Some turquoise contains inclusions of its host rock (known as matrix) that appear as black or brown spider-webbing or patches within the material. Many cutters try to produce stones that exclude the matrix, but sometimes it is so uniformly or finely distributed through the stone that it cannot be avoided. Some people who purchase turquoise jewelry enjoy seeing the matrix within the stone, but as a general rule, turquoise with heavy matrix is less desirable. Some turquoise localities produce material with a characteristic color and appearance. For example, the Sleeping Beauty Mine is known for its light blue turquoise without matrix. Much of the turquoise from the Kingman Mine is bright blue with a spider web of black matrix. The Morenci Mine produces a lot of dark blue turquoise with pyrite in the matrix. Much of the Bisbee turquoise has a bright blue color with a chocolate brown matrix. People who know turquoise can often, but not always, correctly associate a stone with a specific mine. Turquoise cabochons: Turquoise cabochons from many parts of the world, showing a diversity of color and matrix. Image © iStockphoto, IrisGD. The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties.

Inexpensive mineral collections are available in the Geology.com Store . Turquoise Occurrence Turquoise is rarely found in well-formed crystals. Instead it is usually an aggregate of microcrystals. When the microcrystals are packed closely together, the turquoise has a lower porosity, greater durability, and polishes to a higher luster. This luster falls short of being "vitreous" or "glassy." Instead many people describe it as "waxy" or "subvitreous." Porous turquoise is sometimes treated by soaking it in melted wax or impregnating it with polymer plastic to improve its characteristics. Turquoise forms best in an arid climate, and that determines the geography of turquoise sources. Most of the world's turquoise rough is currently produced in the southwestern United States, China, Chile, Egypt, Iran, and Mexico. In these areas, rainfall infiltrates downward through soil and rock, dissolving small amounts of copper. When this water is later evaporated, the copper combines with aluminum and phosphorus to deposit tiny amounts of turquoise on the walls of subsurface fractures. Turquoise can also replace the rock in contact with these waters. If the replacement is complete, a solid mass of turquoise will be formed.

When the replacement is less complete, the host rock will appear as a "matrix" within the turquoise. The matrix can form a "spider web," "patchy" design, or other pattern within the stone. Physical Properties of Turquoise Planerite Al6(PO4)2(OH)8·4H2O Turquoise beads: A collection of Ancestral Puebloan (Anasazi) turquoise beads from Chaco Canyon National Historical Park in New Mexico. These pieces date from about 1050-1100 CE and show the typical materials used in the ancient Chacoan bead and inlay industry. Public domain image from the National Park Service. Turquoise in the United States Most of the turquoise production in the United States has been located in the arid southwest, and most of that production has been in or around deposits of copper. Arizona , New Mexico, and Nevada have all held the position of the leading turquoise-producing state. New Mexico held that position until the 1920s, Nevada held the position until the 1980s, and Arizona is currently the leading state. Significant amounts of turquoise have been produced in California, Colorado, Utah, Texas, and Arkansas.

Most of the turquoise is a byproduct of copper production. The large open-pit copper mines excavate down through the shallow rock units where the turquoise is formed. When turquoise is encountered, the quantity and quality of the material is assessed, and if warranted, a temporary effort is made to recover the gem material. If the value of the turquoise is worth disrupting the mining operation, it will be mined. The mining could be done by copper company employees, but the job is often given to contract miners who are able to come in and quickly recover the turquoise. Turquoise jewelry: Old and new turquoise and silver Navajo bracelets. Image by Silverborders, used here under a Creative Commons license . Turquoise Jewelry and Art The earliest record of turquoise being used in jewelry or in ornaments is from Egypt. There, turquoise has been found in royal burials over 6000 years old. About 4000 years ago, miners in Persia produced a blue variety of turquoise with a "sky blue" or "robin's-egg blue" color. This material was very popular and traded through Asia and into Europe. This is the source of the term "Persian Blue" color.

In North America the earliest known use of turquoise was in the Chaco Canyon area of New Mexico, where the gem was used over 2000 years ago. Ancient artists produced beads, pendants, inlay work, and small sculptures. Rough turquoise and turquoise objects were held in high regard by Native Americans and were traded widely. This spread North American turquoise across the southwest and into South America. These early Native American jewelry designs were simple, and the turquoise was not set in metal findings. In the late 1800s, Native American artists began using coin silver to make jewelry. This work evolved into the turquoise and sterling silver style of Native American jewelry that is popular today. The demand for turquoise and turquoise jewelry rises and falls over time. In the United States there was a surge in demand that began in the 1970s and declined in the 1980s. Demand for turquoise jewelry is always highest in the southwestern states where turquoise mining and Native American artists make turquoise part of the local culture. Synthetic turquoise cabochons: Cabochons made from synthetic turquoise produced in Russia. These stones are 7mm x 5mm ovals.

Synthetic and Imitation Turquoise A small amount of synthetic turquoise was produced by the Gilson Company in the 1980s, and some of their material was used to make jewelry. It was produced in a sky blue color, sometimes with a gray spider webbing. It was a ceramic product with a composition similar to natural turquoise. Synthetic turquoise and turquoise simulants have been produced in Russia and China since the 1970s. They are prolific producers. The material is used to make cabochons, beads, small sculptures, and many other items. A photo on this page shows some synthetic turquoise cabochons made in Russia. There are many different glass, plastic, and ceramic materials with an appearance similar to turquoise. Many of these can easily be distinguished from turquoise by testing their hardness , specific gravity, or other properties. Turquoise rough: A specimen of rough sky blue turquoise in host rock from Mohave County, Arizona. Specimen and photo by Arkenstone / . Look-Alike Materials Howlite and magnesite are light gray to white minerals that often have markings that resemble the spider webbing seen in some turquoise. They can be dyed a turquoise blue color that makes them look very similar to natural turquoise.

These dyed stones fooled many people when they first entered the marketplace and still are mistaken for genuine turquoise by unfamiliar buyers. Dyed stones have damaged the market for genuine turquoise. They have been purchased with the thought that they were turquoise by many people and have produced uncertainty in the mind of many jewelry buyers. This causes some people to avoid turquoise jewelry. Today dyed howlite and magnesite are still used to make mass-produced beads, cabochons, tumbled stones, and other turquoise look-alike items. They are almost ubiquitous in the marketplace. The dye generally does not penetrate deeply into the material. Scratching the back of a stone with a pin will often reveal a white interior. When heavily dyed, a stone must be scratched deeply or be broken to reveal the light interior. A few minerals are sometimes confused with turquoise by people who are unfamiliar with turquoise. These minerals include: variscite, larimar, blue-green chalcedony, lapis lazuli, and chrysocolla. Simple tests will usually differentiate these materials; however, some of the tests are destructive and are usually not suitable for use on finished jewelry items.

Learn About Gemstones Learn About Gemstones Login or I accept the Terms and Coditions Register First name is not valid! Last name is not valid! This is not an email address! Email address is required! This email is already registered! Password is required! Please enter 6 or more characters! Please enter 16 or less characters! Passwords are not same! Terms and Conditions are required! Email or Password is wrong! Gemstones Agate Agate One of the most desired members of the chalcedony family of stones agate has colors arranged in stripes, blended in clouds, or spotted formation. There are countless varieties of agate usually named after their physical characteristics or location of origin. Agate is found in Uruguay, Brazil, the United States, Mexico, Madagascar, Italy, Egypt, India, China, Scotland, and Germany. Alexandrite Alexandrite This unique and very rare gemstone is named after Russian Tsar Alexander II, because it was discovered in 1834, on his 16th birthday. It was found in the Ural Mountains while mining for emeralds.

It is the most valuable gem in the chrysoberyl family because it often changes color from green or bluish-green in daylight to reddish or raspberry in incandescent light. This gemstone has also been found in Myanmar, India, Zimbabwe, Tanzania, and in the late 1980s in Brazil. Almandine Garnet Almandine Garnet This deep red to purple stone is the most common form of the gemstone garnet. The use of garnets as ornamentation dates back to the Bronze Age and many ancient jewelry and crowns have almandine garnets. It is found worldwide including the United States. Amber Amber This organic gem is actually the fossilized hardened resin of the pine tree. The most valuable pieces contain inclusions of insects, plants, or pyrites. Amber is best known as yellow, orange, or brown in color; but the stone ranges from a milky white through a pale lemon yellow to a brown or almost black. There are also examples of red or green, and even blue amber that is rare. The majority of amber that is found today is approximately 30 to 90 million years old.

The largest amber deposits are found in the Dominican Republic and the seabed of the Baltic. Amethyst Amethyst The name comes from the ancient Greek word, amethustos, meaning not intoxicated, and a reference to the belief that the stone protected its wearer from drunkenness. Brazil and Zambia are the primary source of amethysts mined today and is also found in Uruguay, Bolivia, Canada, India, Madagascar, Mexico, Namibi, Russia, Sri Lanka and the Arizona in the United States. The most important amethyst deposits are in Brazil, namely the “Palmeira” amethysts of Rio Grande do Sul and the “Maraba” amethysts of Para. Ametrine Ametrine A very unique member of the quartz family ametrine is a mixture of amethyst and citrine with the stone displaying both zones of purple and yellow or orange. The color zones visible within the stone are due to differing oxidation states of iron within the crystal while it was forming. Bolivia is the major world producer of ametrine. Andalusite Andalusite This gemstone was first found in Andalusia, Spain in 1789. The most common color is a bronzed red coupled with golden green.

Often called a poor man’s alexandrite, these stones are found in sizes less than 1 ct. and are mined in Sri Lanka, Brazil, Australia, and Spain. Aquamarine Aquamarine A member of the beryl family of stones, aquamarine was often thought to resemble the clear, blue water of the Mediterranean by the Greeks and Romans. Like the sea water it is named for its color can range from blue to green blue. These stones were symbols of youth and everlasting happiness to the Romans. Aquamarine is mined in Brazil, China, India, Russia and the United States. Bloodstone Bloodstone A member of the quartz/chalcedony family of stones it is green spotted with red dots of iron oxide. It is also known as heliotrope because the ancient Greeks noticed how the polished stones reflected the sun. India is the main source of this stone but it is also found in Australia, China, South America, and the United States. Carnelian Carnelian A member of the quartz/chalcedony family it derived its name from the cornel cherry because of its red color.

Carnelian is one of the oldest known gemstones; it was one of the 12 gemstones mentioned in the Bible as appearing on the breastplate of Aaron. Cat’s Eye Cat's Eye This phenomenon that is gemologically called chatoyancy, derives its name from the French for “eye of the cat” because the effect resembles just that, an eye of a cat. The most well known cat’s eye is Chrysoberyl. Cat’s eyes appear in other stones but need to be referred to by the name of the stone it appears. Chalcedony Chalcedony This quartz family of gemstones has a waxy luster and can be semitransparent or translucent. It can occur in every color in the rainbow. Agate, carnelian, chrysoprase, heliotrope and onyx are all members of the chalcedony family. As early as the Bronze Age chalcedony was highly prized and used in the Mediterranean region as adornments. Chrome Diopside Chrome Diopside This green gemstone color commonly ranges from light to dark green. Its name is derived from the melding of two Greek words di and opsis meaning double vision.

The rich green color is caused by chromium which also gives emerald its green color. Primarily mined in Russia it is also found in India, South Africa, the United States, Finland, and Myanmar. Chrysoprase Chrysoprase This apple green stone derives its color from trace amounts of nickel and is the rarest of the chalcedony family of stones. Legend says that it enhances grace and equilibrium and in some areas of the world it was thought to increase fertility. It is found in Australia, Brazil, Russia and the United States. Citrine Citrine A member of the quartz family this stone color ranges from pale yellow to brown. The name comes from the French word for lemon, citron. Citrine was carried as protection against snake venom and evil thoughts by ancient people. It is also believed to make its wearer lighthearted. Deposits of this stone are found in Brazil, Russia, France, and Madagascar. Coral Coral A gemological cousin to pearl, it is also known as red coral. Red corals are found growing at the bottom of a sea, in dark environs.

In Greek mythology when Medusa was slain her head rested on a riverbank and as her blood drained into the sea it changed the seaweed it touched into red coral. First harvested in the Mediterranean Sea it is also found at Atlantic sites near the Strait of Gibraltar and at the Cape Verde Islands. Similar species are found in the western Pacific near Japan and Taiwan. Demantoid Garnet Demantoid Garnet A member of the garnet group this green gemstone gets it color from iron. Its name means diamond in Dutch and has a higher dispersion (brilliance) than diamond. While garnets were known since ancient times the demantoid variety was not discovered until the mid 1800s in Russia’s Ural Mountains. This gem is considered one of the most valuable garnets because of its rarity. Aside from Russia this stone is mined in Namibia, Italy, and Iran. Emerald Emerald The favorite stone of Egyptian Queen Cleopatra, emerald is a member of the beryl family of gemstones. The mineral chromium is what gives the emerald its color, the higher the chromium the more intense the color. Emeralds were mined by the ancient Egyptians and their name comes from the Greek word smaragdos meaning green stone.

The finest emeralds are found in Columbia but emeralds are also found in Zambia, Zimbabwe, Brazil, Russia, and Afghanistan. Garnet Garnet This durable stone occurs in many colors in many countries around the world. Pyrope, red, purple, spessartite, orange; tsavorite, green; and almandite, brown are just a few of the members of the family. The name is derived from the Latin word granum meaning grain. These stones were considered to symbolize faith, constancy, and truth by ancient people as well as having strong curative powers. Gemstone Diamond Diamond The hardest material known to man, diamond is the only gemstone primarily comprised of one element, carbon. One of the oldest known gems, diamonds were mined in India as far back as 400 B.C. The largest diamond ever found was the Cullinan, a 3,106 ct. behemoth, found in 1905. It was cut into 105 stones, two of which reside in the British Crown Jewels. Hessonite Garnet Hessonite Garnet This member of the garnet family is brownish-red to yellowish-orange and is often called the cinnamon stone.

Hessonite in Greek means inferior and refers to the stone being less hard than other garnets. It mainly comes from Sri Lanka and India but has also been found in Brazil and the United States. Iolite Iolite The name Iolite comes from the Greek ios which means violet. The most treasured color is a vivid violet blue. Iolite is a pleochoric stone which means that different color shades can be seen when viewed at different angles. The largest iolite ever found was a 24,000 ct. stone in Wyoming. Besides the United States, this gemstone is also found in Brazil, Sri Lanka, Canada, and Madagascar. Jade Jade This stone ranges from light to dark green, yellow, brown, white, black and grey. The most valued color is the imperial green color that can rival the color of emeralds. Examples of jade items used in the Neolithic period have been found in China. This stone is mined in China, Myanmar, Russia, and South America. There are two types of jade: jadeite and nephrite. Kunzite Kunzite This pink to violet gemstone is also known as evening stone because the color fades in prolonged exposure to sunlight.

This relative newcomer to gemstone family was first identified in Connecticut by Tiffany & Co. gemologist and namesake George Kunz. The first significant deposits were discovered in California in 1902. Today, most kunzite is mined in Brazil, Afghanistan, and Madagascar. Kyanite Kyanite This gemstone derives its name from the Greek word kuanos that means deep blue. Kyanite can appear as cabochon or faceted stone and range in color from cobalt blue to light blue/green and colorless. It is considered an exotic gemstone because it is not often used in jewelry. Labradorite Labradorite This stone is named after the Labrador Peninsula in Canada where it was first discovered in 1770. This stone can be gray, brown, green, blue, or yellow with a milky iridescence and metallic luster, when polished, is why it sought as a gemstone. Aside from Canada this stone is found in Norway, Finland, and Madagascar. Lapis Lazuli Lapis Lazuli The intense blue of this naturally occurring stone has been prized for its color by ancient peoples. It takes its name from Latin and Arabic words that translate to heaven-blue stone.

The name is sometimes shortened to Lapis and while the stone is hard it can be carved. This stone has been mined in Afghanistan for more than 6,000 years and deposits are also found in Russia, Argentina, Myanmar, Pakistan, Canada, India, and in the United States. Malachite Malachite This opaque, green-banded stone derives its intense color from copper. It is named after the Greek word for “mallow” because it resembles the leaves of the mallow plant. According to archeological evidence it was mined more than three centuries ago in Israel. Large quantities of the stone is found in Russia but it is also found in lesser quantities around the world, including Africa, Mexico, Australia, France, Israel and the southwestern United States. Moonstone Moonstone This opaque stone gets its name from the Romans who believed it was born from solidified rays of the moon. This stone when formed has thin, flat layers and the seams between layers have a pearly opalescent luster. This stone is found in Australia, Austria, Mexico, Madagascar, Myanmar, Norway, India, Sri Lanka, and the United States.

Morganite Morganite This beautiful pink stone is a member of the beryl family along with emerald and aquamarine. This gemstone was introduced to the world in 1911 and was named after famous banker and gem collector J. P. Morgan. It is found mainly in Brazil but also in Afghanistan, Madagascar, and California in the United States. Onyx Onyx A member of the quartz/chalcedony family, onyx is actually dyed agate. Its name comes from the Greek word, onux, meaning fingernail. Onyx actually dates back to ancient Egypt where it was used to make bowls and other pottery-like items. It is mined worldwide including Brazil, India, Madagascar, and the United States. Opal Opal This gemstone is primarily mined in Australia and stones come in a full spectrum of color. The most common are the milky white and green stones while the red against black are the most rare. Opals are valued by the fire or play of color when looked at from different angles. Deposits of these stones are also found in the United States, Czech Republic, Turkey, Indonesia, Brazil, Ethiopia, and Guatemala.

Pearl Pearl This naturally forming gem is produced within the soft tissue of a living shelled mollusk, such as an oyster. Cultured pearls can be divided into two categories: beaded salt-water and non-beaded freshwater pearls. The iridescence of pearls is what makes them highly prized and range in color from white to cream-golden, green, blue, black, and rainbow. Cultured pearl farms are found in China, Japan, Australia, Indonesia, and the Philippines. Peridot Peridot This gemstone is an ancient one, mentioned in the Bible and one of the few gemstones that exist in only one color, green. The Romans called this gem “evening emerald” since the green color didn’t darken at night and was still visible by lamplight. A member of the olivine family of stones, its color is derived from traces of iron introduced during its formation. Main deposits are found in Pakistan, China, Vietnam, and Arizona in the United States. Rhodolite Garnet Rhodolite Garnet Named for the Greek word meaning rose this beautiful gem is a mixture of pyrope and almandite garnets.

First discovered in North Carolina in 1882 the color of this gemstone ranges from purplish red to reddish purple. In 1996 a 19th century rhodolite brooch once owned by Jacqueline Kennedy Onassis sold for $145,000 at auction. Rose Quartz Rose Quartz A sister to amethyst, rose quartz exhibits a transparent pale pink to rose-red hue. Sometimes called the gem of the heart its history can be traced back thousands of years. The main source is Brazil but it is also found in Europe, Asia, Africa, South America, Canada and the United States. Ruby Ruby Known to the ancients as “the King of Gems” ruby dates back centuries and is referenced in the Bible. The name of this gemstone comes from the Latin word ruber meaning red. Second only to diamonds in hardness it is the red cousin of sapphires. The highest quality rubies are very rare and can be worth more than diamonds. These gemstones are mined in Myanmar, Thailand, Cambodia, India, Afghanistan, Pakistan, and Sri Lanka. Ruby is used to commemorate 15th and 40th wedding anniversaries.

Sapphire Sapphire The most well known of the sapphire family is the blue stone that is only second in hardness to diamonds and known as the gem of heaven because of its rich blue color. The use of sapphires as adornment dates back, as early as, the 7th century B.C. One of the most famous sapphires is the 104 ct. Stewart Sapphire mounted in the British Imperial State Crown. Sapphires are most prevalent in Australia, Thailand, Sri Lanka, China, Madagascar, Africa, and Montana in the United States. Smoky Quartz Smoky Quartz There are very few brown gemstones and smoky quartz is certainly the most well known. This national gem of Scotland was used by the Chinese to make sunglasses in the 12th century. Brazil is the world’s largest supplier but it can be found many places including the United State’s Pikes Peak region of Colorado. Spessartite Garnet Spessartite Garnet This member of the garnet family of stones is named after the Spessart region in Bavaria, Germany where it was first found in the 1800s.

The best specimens have a bright orange “fanta” color and are called Mandarin garnets. Mandarins are found in Namibia and Nigeria. Other locales for spessartite include: Brazil, Myanmar, Mozambique, and the United States. Sphene Sphene First discovered in the late 1700”s sphene is one of only three gemstones with a higher dispersion and more brilliant than a diamond. Sphene is a very rare brilliant gem that can occur in several colors including yellowish green, green, orange or brown. The name "sphene" comes from the Greek word for "wedge" referring to its typical crystal shape. Its mineralogical name is Titanite because of its titanium content. Intense green sphene is also known as "chrome sphene", due to the coloring agent chromium. Sphene deposits are found in Brazil, Myanmar, India, Kenya, Madagascar, Mexico, Austria, Sri Lanka Ceylon and the U.S. Spinel Spinel This “step-child” of the gem world, has never received the recognition it deserves. Historically, many famous spinels were originally thought to be other, more “popular” gemstones.

Today however, spinels can be some of the most gorgeous gems you will find. These gemstones can be red, blue, mauve, dark green, brown, and black and every color in between. Some spinels have a very “electric or neon” tone. The name is derived from the Latin word spina, meaning thorn. These stones are prevalent in Sri Lanka, Afghanistan, Africa, Myanmar, and Vietnam. Sunstone Sunstone Sunstone is a gem-quality member of the feldspar family and is famed for its aventurescence, often referred to as 'schiller'. Sunstone is typically orange to reddish in color and its spangled appearance is reminiscent of the sun, hence its name 'sunstone'. The spangles can be red in color or more rarely green or blue which is caused by light reflections from tiny hematite or goethite platelets. Some of the more significant, notable deposits come from India, Canada, Madagascar, Norway, Russia and the USA (Oregon, Pennsylvania, North Carolina and Utah). Oregon is famous for producing sunstone included with traces of copper, and named it the state’s official gemstone.

Tanzanite Tanzanite This blue/purple gemstone was first discovered in 1967 in northern Tanzania at the base of Mt. Kilimanjaro. Officially called blue zoisite it was marketed as tanzanite by Tiffany & Co. who wanted to capitalize on the rarity of this gem that is only found in Tanzania. Tanzanite is the only gem discovered in the last 100 years that has been added to the birthstone list, as a December birthstone. Topaz Topaz Is a stone of many colors but pure topaz is colorless and transparent. It is the impurities that give life to the stone. Topaz comes in brown, orange, gray, yellow, blue, green, and pink. While we think of topaz as being blue most of the time, naturally occurring blue topaz is quite rare. This stone is mined in Russia, Afghanistan, Sri Lanka, Australia, Nigeria and the United States. Tourmaline Tourmaline This stone consists of more color variants than any other gemstone in the world. Usually rich in iron these stones run from black to bluish-black to deep brown.

Depending on the trace elements colors can be blue, green, red, yellow, and pink. Crystals can be bi-colored or multicolored and some stones change color when viewed from different angles. Tourmaline from Sri Lanka was first introduced to Europe by the Dutch East India Company. Today tourmaline is mined in Brazil, Africa, Tanzania, Kenya, Afghanistan, Pakistan and the United States. Tsavorite Garnet Tsavorite Garnet A member of the garnet family this stone is relatively new on the gemological scene. A deposit was found in 1967 by a British gem prospector in northeast Tanzania. This vivid green stone is believed to be 200 times more rare than emerald. It was also found in nearby Kenya in 1971 by the same prospector who was granted a permit to mine it. The public was introduced to the stone by Tiffany and Co in 1974. The only other place it is found on the planet is Madagascar. Turquoise Turquoise This opaque, blue/green mineral derives its color from a mixture of copper and aluminum. It has been prized as an ornamental stone for thousands of years. It is prominently displayed on the burial mask of King Tut.

The substance has been known by many names but turquoise comes from an Old French word for Turkish, because the mineral was first brought to Europe from the Turkish Empire or modern day Iran. Turquoise is a byproduct of copper mining and the southwest United States is a significant source. Zircon Zircon This mineral’s natural colors include yellow-golden, red, blue, and green. The colorless version of this stone can be mistaken for a diamond and is known as “Matura diamond.” Ancient people believed zircon brought prosperity, honor, respect and wisdom to its wearers; and it also was thought of as a symbol of honesty and contentment. American Gemstones American Gemstones Sunstone from Oregon The United States is one of the main consumers of colored gemstones in the world, but is not known as a important gemstone producer. This was not always the case. Back in the first decade of the 20th century, the US was the leading tourmaline producer in the world, with important mines in Maine and California. Commercial gemstone mining is still active in eight states of the US. Surprisingly, the top state (based on total value produced) is Tennessee.

This is because the American Pearl Company operates the only freshwater pearl farm in the country in Tennessee. Watermelon Crystal from California The second most important state in commercial gemstone mining is Arizona, with significant deposits of peridot and turquoise . Arizona is also known for agate , jasper , petrified wood, garnet and opal . Turquoise is the most valuable gemstone produced in Arizona, though production is labor intensive because careful hand extraction is required. Oregon is internationally famous for its sunstone , a feldspar mineral. Sunstone is a type of labradorite that contains large numbers of microscopic copper platelets that produce an interesting play of color. Oregon also produces a variety of agate, jasper, and obsidian. Tourmaline was discovered in California at the end of the nineteenth century, and between 1898 and 1914 the Himalaya Mine in San Diego County was the world's largest producer of tourmaline. Turquoise production also has a long history in California, especially in San Bernardino County, but the deposits are no longer active. There are still tourmaline reserves in California, but the cost of mining tourmaline has become prohibitively high.

Most of the gemstones found in the US are in the west, and Idaho, Montana and Nevada have produced notable stones. Idaho produces small quantities of various gem types, including agate, jasper, garnet and opal. Idaho is well-known as a source for the rare star garnet. Montana is famed for its sapphires from Yogo Gulch. A range of colors are found, including blue, green, pink, purple, yellow and orange. At one time, Nevada produced fine turquoise but recent gem production has mainly been opal from Virgin Valley. Peridot Rough from Arizona Sapphire Rough from Montana Arkansas is noted for its quartz , especially rock crystal, which is produced and sold as mineral specimens and also faceted for gemstones. It is also fashioned into beads, carvings , spheres and other decorative items. First Published: December-26-2009 Last Updated: June-26-2014 © 2005-2016 GemSelect.com all rights reserved. Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited.

See more related information below Treasure Hunting For Turquoise Treasure Hunting For Turquoise Turquoise is possibly the most valuable, non-transparent mineral used in jewelry. It has been mined since at least 6000 BC by Egyptians. Like other opaque such as coral, turquoise is commonly sold by the size in millimeters rather than by weight. Turquoise is usually found sandstone layers and can be seen as splotches or as a network of brown or black veins running through the sandstone. There are many small-scale mining operations that are worked by hand. Only one mine in Apache Canyon California operates at a commercial capacity today. With a hardness of just under 6, about the hardness of window glass, this gemstone takes a good polish. It comes in white, blue, green, brown, yellow and all of the shades in between. The value of the turquoise you will find is determined by the richness of color. Robin’s egg is usually the most valuable. The more of a green hug or lightening of color will decrease the value. Turquoise should never be soft or chalky in color.

Turquoise is typically found in the arid regions of the world and some high quality gemstones have been found in the Southwest United States such as Arizona, California, Colorado, New Mexico and Nevada. More that 120 mines have produced significant quantities of gem quality turquoise in Nevada. Nevada mines are primarily worked for the gemstone as apposed to other mining areas where turquoise is usually the result of the by product of other mining activities. The geological formation of Nevada turquoise, it is hard and dense and usually does not require any treatment or enhancements to be used in jewelry. The Royston mining district located near Tonapah, Nevada conducts tours of the mining facility Wednesday through Saturday excluding holidays. For $100 per person you will get a bucket to fill up by picking through the tailing piles. You will need to bring gloves, hat, sunscreen, water, and a good pair of shoes. The mines in Royston have been in operation since 1902 and by 1915 over $5,000,000 worth of turquoise has been removed from the mines. It was believed to have been the largest single producing turquoise mine in America at that time.

The Otteson’s Mine also offers mine tours, Wednesday through Friday excluding holidays. For $50 per person you will get a bucket to fill up by picking through the tailing piles. Turquoise is found throughout the Southwest United States. Always contact the states Bureau of Land Management for any fees or permit requirements before treasure hunting on public land. Also get permission from any land owners before hunting on private property. In Arizona turquoise has been found near Albuquerque, Bisbee, Cave Creek, Globe, Kingman, Turquoise and Birdeyes mountains. In California turquoise has been found in San Bernardo, Imperial, and Inyo counties. In Colorado, search Conejos, Lake, El Paso and Saguache Counties. In Nevada, search Clark, Elko, Esmeralda County, Eureka, Lander, Mineral County and Nye counties. New Mexico, Eddy, Grant, Otero, and Santa Fe counties. Tools you will need to hunt for turquoise; Pick Axe, rock hammer, gloves, safety glasses, bucket. Remember you are searching arid regions of the world so proper clothing is a must. Wear clothing in layers because weather can change very rapidly in these areas. Water, hat and a good sunscreen is a must.

About the Author: David Cowley has created numerous articles on Treasure Hunting. He has also created a Web Site dedicated to Treasure Hunting. Visit Permanent Link: David Cowley David Cowley has created numerous articles on Treasure Hunting. He has also created a Web Site dedicated to Treasure Hunting. Visit Treasure Hunting Types of gemstones - gemstones guide A to Z Agate A unique variety of the quartz family, agate is relatively common and affordable. It has an average hardness of 6.5-7 on the Mohs scale. Agate is known for the multicolored bands that might be likened to tiger stripes or tree rings. This beautiful feature is what makes agate such a popular gemstone. Some evidence shows that agate has been used by Human beings for up to 15,000 years. Today Agate is mined in the United States, Mexico, Germany, Italy, Brazil, China, India, Africa and a number of other countries. Alexandrite A variety of the mineral chrysoberyl, top quality alexandrite is very rare and very valuable. At 8.5 on Mohs scale, its hardness is considered to be relatively good.

High quality alexandrite dramatically changes color from green in fluorescent light and daylight to purplish red in incandescent light. Discovered in Russia in 1830 and named after Czar Alexander II, it was soon adopted as the national stone of Russia. Its colors correspond to the Russian imperial colors. Other forms of alexandrite are mined in Brazil, Tanzania, Sri Lanka, India and Madagascar. alexandrite is also an alternative June birthstone in the United States. Amethyst A variety of the quartz family, amethyst is considered to be a common and affordable. This colored stone has a hardness of 7 on Mohs scale, and varies in color from light lilac to deep purple. Amethyst is very sensitive to heat and sunlight. It may lose all of its color when exposed to strong UV rays for extended periods of time. Amethyst was believed by many cultures to possess various supernatural beneficial properties such as promoting piety and preventing alcohol intoxication. Mined in Brazil, Uruguay, Bolivia, Tanzania, Zambia, Namibia and small amounts can also be found in the United States. It is the February birthstone in the US.

Aquamarine A variety of the beryl mineral, aquamarine is named for its sea-like color, which can range from pastel blue, to deep blue, to greenish or yellowish blue. Deep blue aquamarine stones are considered to be the most valuable of their kind. Aquamarine has a good hardness of 7.5-8 on the Mohs scale. It is frequently used in modern designs and is believed to be a lucky stone in several cultures. It is mined mainly in Brazil, Zambia, Mozambique, Angola, Nigeria and Madagascar, and is the March birthstone in the United States. Citrine A member of the quartz family, citrine is typically more affordable than amethyst. This bright gemstone has a hardness of 7 on the Mohs scale. Its color ranges from bright yellow to honey and orange-brown. The name citrine comes from the French word for lemon, appropriately describing this colored stone's warm, inviting hue. It is mined in Brazil and Bolivia, where it is common and plentiful. Citrine is frequently exposed to heat enhancement in order to improve or modify its color. It is an alternative November birthstone in the United States. Coral Coral is an organic gemstone.

Genuine, untreated coral is very rare and therefore very valuable. It is extremely delicate, its hardness measuring at approximately 3.5-4 on the Mohs scale. Coral is composed of calcium carbonate, which is secreted by small sea polyps in order to create their own natural protective habitat. Commercial coral is never harvested from protected reefs or banks, and harvesters have recently become more careful with their harvesting methods, dispatching professional divers to carefully collect coral branches so as to avoid damaging the sea organisms within. Most coral used in jewelry comes from Sicily or Sardinia. Coral ranges in color from reds and oranges to whites and even blues. Emerald The emerald is a member of the beryl family. It is very rare and commands relatively high prices on the market. Because inclusion-free emeralds are extremely infrequent, the detection of inclusions minimally impacts the value of an emerald, if at all; only very severe and deep inclusions will reduce an emerald's value. The most highly-priced emeralds exhibit a bright grass-like green. Emeralds have a very good hardness of 7.5-8 on the Mohs scale.

They are known worldwide for their exquisite green hue and have been embraced by mankind for over 4,000 years. Mentions of emeralds appear in the myths, legends and rituals of the Incas, the Egyptians, the Indian Moguls and the Ancient Greeks. They are believed by many cultures to have positive supernatural powers. Their green color can range from a very light yellowish green to a deep, dark, sometimes bluish tint. Currently, most emeralds are mined in Columbia, Brazil, Zambia, Zimbabwe, Afghanistan and Madagascar. The emerald is the May birthstone in the United States. Garnet Garnet is the name of an entire family of stones that can be found in a wide spectrum of colors. The value of any garnet depends entirely on color, size and corresponding rarity. While deep red is the most common, affordable and traditional garnet color, garnets may range from green, orange, and yellow to earthier sepia hues; they come in almost every color, other than blue. Garnets have a good hardness of 7.5-8 on the Mohs scale. These gemstones have been valued by mankind for thousands of years and are mentioned most famously in the story of Noah's Ark.

Garnets in common colors hail from India, Sri Lanka, Thailand, South Africa and the United States, while the more exotic garnet colors are mined in East Africa and Russia. The garnet is the January birthstone in the United States. Jade Jade is an umbrella term for two stones: jadeite and nephrite. Jadeite displays colors which include green, white, pink, red, black, brown, and violet. Nephrite typically displays mid to dark green or gray-green, but it can also be white, yellowish, or reddish. Only the finest jades have evenly distributed color. Jade has been valued by both Eastern and Western countries for over 7,000 years. It is considered an especially precious symbol of royalty, compassion, goodness, beauty, modesty and more. Jades have an average hardness of 6.5-7 on the Mohs scale, but they are extremely tough. Because of this toughness, jades have been used by early civilizations to make knives, axes, tools and weaponry. They are well known for being an effective remedy for kidney ailments.

The word jadeite originated from the Spanish 'piedra de ijada', and the word nephrite originated from the Latin' lapis nephriticus', both meaning 'loin stone'. Moonstone Moonstone is a member of the large feldspar family of minerals which includes about two-thirds of all stones on earth. It has a hardness of 6-6.5 on the Mohs scale, and exhibits a wide range of colors from green, brown, yellow, gray pink, rainbow, and colorless to very rare blues. High quality moonstones display a blueish luster. Generally thought to resemble moonshine, the token characteristic of the moonstone is its white shimmery glow. History holds that the Romans and Hindus thought the stone was formed from actual pieces of moonlight, and many still believe that the future may be seen in its ethereal glimmer. The unique blue-glow of light that slides across the surface of the stone is caused by a type of light refraction called adularescence. Most moonstones come from Sri Lanka, but some are mined in India, Burma, Mexico and Madagascar. The moonstone is the June birthstone in Europe.

Opal The word opal originates from the Greek 'opallos', meaning ' color change', referring to the color of the opal which seems to vary when tilted under light. This phenomenon occurs due to an internal diffraction of light which disperses a spectrum of iridescent colors. The opal family is well known for its special rainbow color play, and is available in an almost infinite array of hues including black, white, colorless, yellow, reddish, green, blue and multi-colored. The opal has an average hardness of 5.5-6 on the Mohs Scale. A myriad of superstitious legends exist regarding the origin of opals and the supernatural powers that these stones may possess. The main origin of the opal is Australia, with Mexico and the US serving as its secondary sources. Opal is the October birthstone in the United States. Pearl The most valuable of all organic gemstones, pearls are created when an oyster senses an irritant within its soft shelled mouth and then coats it with layers of nacre. Today, almost all pearls on the market are cultured by artificially introducing a small bead or shell into the mouth of an oyster.

The majority of pearls are cultured in Japan, but many are harvested in China and the South Pacific. Pearls range in size, shape and color: some are large, round and white while others are small, amorphous, and black. Pearls have always been considered classic gemstones, symbolic of beauty and dignity. The pearl is the zodiac gemstone for Cancer. Learn more about pearl types and characteristics in our Pearl Education pages. Peridot A member of the olivine family, peridot comes in a variety of shades of green. The signature lime-green peridot is a characteristic of the mineral itself, rather than that of a foreign element. Peridot is one of the sole gemstones that can be found in only one color. It has a hardness of 6.5-7 on the Mohs scale. It is believed by some that peridot enhances the effectiveness of any medicine. According to others, peridot protects against nightmares. An indigenous Hawaiian myth suggests that a peridot stone is a tear of Pele, the Hawaiian fire and volcano goddess. Most peridot is mined in Arizona; other sources being China, Burma, and Pakistan. Peridot is the August birthstone in the United States.

Ruby Ruby is the red manifestation of corundum; all other colors of corundum are referred to as sapphire. Due to its durability, brilliance and bewitching red color, it has for thousands of years been considered to be one of the most valuable gemstones. Larger rubies, being rarer, command the highest prices. This precious gemstone has a very good hardness of 9 on the Mohs scale. Owing to its red color, the ruby is commonly associated with passion, love, power, warmth, blood, and fire. Rubies have been worn by warriors to give them courage, by kings to give them power, and have been gifted as an expression of undying love. The highest quality rubies exhibit a deep vivid red or purplish red. The ruby is the July birthstone in the United States. Sapphire Sapphire is a member of the corundum family. Sapphires most commonly occur in blue, and vivid, pure, deep blues are the most valuable. For thousands of years, sapphire has been associated solely with the color blue, its name originating from the Greek word 'sappheiros', meaning blue.

However, sapphires can be found in every color besides red, as red sapphires are called rubies. Throughout the course of history, this gem has been worn as a protective amulet, as a symbol of harmony, loyalty and friendship, and as a romantic token. The stone has a very good hardness of 9 on the Mohs scale. Sri Lanka is the biggest producer of sapphires, but they are also mined in Kenya, Burma, Tanzania, Kashmir, Madagascar, Thailand, Vietnam, Cambodia, Laos, Australia, and the United States. The sapphire is the September birthstone in the United States. Tanzanite A member of the zoisite family of minerals, tanzanite is found only in shades of blue or purple, the most popular being a violet-blue. While tanzanite is typically heat treated to enhance its blue color, it is naturally trichroic, meaning that it displays three different colors (blue, purple and bronze) when viewed from different angles. Tanzanite exhibits a hardness of 6.5-7 on the Mohs scale. It gets its name from the country of Tanzania, the only place in the world where it is found.

Tanzanite was discovered as recently as 1967, and was christened by colored stone experts to be "the gemstone of the 20th century." Owing to its fast growing popularity, the American Gem Trade Association added it as an alternative December birthstone in the United States in 2002. Topaz Topaz is one of the most common gemstones worldwide. It has a very good hardness of 8 on the Mohs scale. Topaz comes in a rainbow of colors, the most valuable of which are the red, pink and orange stones which are mined in Brazil, Pakistan and Russia. Colorless topaz is mined in Sri Lanka, Nigeria and China. Blue topaz is colorless in its rough form, and takes on its blue hue only after exposure to irradiation enhancement. It is quite sensitive to heat and sunlight, and may lose all of its color when exposed to strong UV rays for extended periods of time. Many cultures have claimed that topaz has mythical and magical strengthening powers. It is the traditional November birthstone and the alternative December birthstone in the United States.

Tourmaline The word tourmaline was derived from the Sinhalese words 'tura mali', meaning 'mixed colored'. As its name indicates, tourmaline is found in a vast array of colors and color mixtures, more than any other gemstone in the world. For this reason, no two pieces of tourmaline are ever identical. Since many of its colors look similar to the colors of other gemstones, many tourmaline stones have been misidentified as rubies and sapphires. This colorful gem exhibits a good hardness of 7-7.5 on the Mohs scale. The rarest colors, which include copper and electric blue, are the most valuable. Many magical powers have been attributed to tourmaline over the ages, including the power to enhance artistic creativity. Although Brazil is the most common source of tourmaline, the stone is also mined in Tanzania, Madagascar, Australia, Stri Lanka, the United States, and Russia. It is an alternative October birthstone in the United States. Turquoise A member of the copper family, turquoise is one of the oldest gemstones known to man, having been treasured by countless ancient civilizations across the globe.

It is thought to have originated in Iran, where many Persians wore turquoise on their turbans to protect against the evil eye. Native Americans, Egyptians, Chinese and Tibetans also believe turquoise holds spiritual and protective powers. Turquoise is known for its light blue color, which can range from greenish-blue to sky blue, and at times exhibits yellow, black, gray, or even brown veining. This renowned gemstone exhibits an average hardness of 6 on the Mohs scale. As Iranian sources of turquoise have been nearly depleted over the centuries, the stone is now mined mainly in the southwestern United States, Mexico, Afghanistan, Israel and China. Turquoise is the December birthstone in the United States.

Question: What gemstone has a blue-green color and is common in the Southwest United States?
Answer: Turquoise