Spinel

Richard Hughes has been a leading ruby expert for decades. Learn how he got started and his tips for newcomers to the world of rubies.

Large, beautiful, and historically important, these eight famous sapphires have fascinating stories to tell. Learn what makes them so special.…

With dark bodies and colorful sheens, beautiful Tahitian pearls have mesmerized jewelry lovers for decades. Learn more about these and other…

Made from two or more materials, assembled gems can make durable and affordable jewelry. Learn more about gemstone doublets, triplets, and other…

Opal cabochons can fetch high prices but may be difficult to cut. These tips for carving opals can help gem cutters make the most of these beautiful…

Cutting opals is a delight, but gem cutters may encounter a number of challenges when cabbing. However, with some carving techniques and a little…

An assembled gemstone is constructed from two or more combined materials. Gemstone doublets and triplets, intarsias, and rhinestones are all…

Why are some gems so rare in nature? Learn which elements in the Earth’s crust are the rarest and how these ingredients help form uncommon gemstones.…

This table contains a selection of minerals gemologists may encounter as jewelry stones or gem specimens. The gems are sorted by their crystal…