Purple variety of the mineral quartz, often forms large, six-sided crystals. Fine velvety-colored gems come from African and South American mines. In demand for jewelry at all price points.  

Ametrine, one of the rarest types of transparent quartz, combines two colors: amethyst’s purple and citrine’s orange-to-yellow, growing together in a single crystal.

Blue to slightly greenish-blue variety of the mineral beryl. Crystals are sometimes big enough to cut fashioned gems of more than 100 carats. Well-formed crystals might make superb mineral specimens.

The most valued variety of beryl, emerald was once cherished by Spanish conquistadors, Inca kings, Moguls, and pharaohs. Today, fine gems come from Africa, South America, and Central Asia.

Citrine’s color comes from traces of iron. It’s perhaps the most popular and frequently purchased yellow gemstone and an attractive alternative for topaz as well as for yellow sapphire.

This hardest gem of all is made of just one element: carbon. It’s valued for its colorless nature and purity. Most diamonds are primeval—over a billion years old—and form deep within the earth.

Fine color diamonds are the most rare and costly of all gemstones. Their ranks include the world’s most famous jewel—the Hope—and the most expensive gem ever auctioned—The Graff Pink.

The garnet group of related mineral species offers gems of every hue, including fiery red pyrope, vibrant orange spessartine, and rare intense-green varieties of grossular and andradite.

Yellow-green gem variety of the mineral olivine. Found as nodules in volcanic rock, occasionally as crystals lining veins in mountains of Myanmar and Pakistan, and occasionally inside meteorites

Produced in the bodies of marine and freshwater mollusks naturally or cultured by people with great care. Lustrous, smooth, subtly-colored pearls are jewelry staples, especially as strands

Trace amounts of manganese give this pink to violet variety of spodumene its feminine glow. A relative newcomer to the gemstone stage, kunzite was only confirmed as a unique variety of spodumene in the early part of the twentieth century.

Prized by civilizations from ancient China to the Aztecs and Mayans of Central America, jade is crafted into objects of stunning artistry

Known in the jewelry trade as iolite, this mineral is known as cordierite to geologists and mineralogists. It was named after French mineralogist Pierre Cordier.

Like its cousins emerald and aquamarine, morganite is a variety of the beryl mineral species. This gem gets its subtle blush when a trace amount of manganese makes its way into morganite’s crystal structure.

Opal’s microscopic arrays of stacked silica spheres diffract light into a blaze of flashing colors. An opal’s color range and pattern help determine its value.

Depending on their trace element content, sapphire varieties of the mineral corundum might be blue, yellow, green, orange, pink, purple or even show a six-rayed star if cut as a cabochon.

Although frequently confused with ruby, spinel stands on its own merits. Available in a striking array of colors, its long history includes many famous large spinels still in existence.

Traces of chromium give this red variety of the mineral corundum its rich color. Long valued by humans of many cultures. In ancient Sanskrit, ruby was called ratnaraj, or “king of precious stones.”

Named for Tanzania, the country where it was discovered in 1967, tanzanite is the blue-to-violet or purple variety of the mineral zoisite. It’s become one of the most popular of colored gemstones.

Colorless topaz treated to blue is a mass-market gem. Fine pink-to-red, purple, or orange gems are one-of-a-kind pieces. Top sources include Ouro Prêto, Brazil, and Russia's Ural Mountains

Comes in many colors, including the remarkable intense violet-to-blue gems particular to Paraíba, Brazil, and similar blues from Africa. Favorite of mineral collectors.

Ancient peoples from Egypt to Mesoamerica and China treasured this vivid blue gem. It’s a rare phosphate of copper that only forms in the earth’s most dry and barren regions.

Sunstone, a member of the feldspar group, can be an orthoclase feldspar or a plagioclase feldspar, depending on chemistry. Both can show aventurescence. “Sunstone” applies to the gem’s appearance.

Optical properties make it bright and lustrous. Best known for its brilliant blue hues; also comes in warm autumnal yellows and reddish browns, as well as red and green hues.