Diamond Buying and the 4 Cs, Part 4: Assessing Diamond Clarity

What is Clarity?

Clarity covers all things in a stone that affect the free passage of light. Thus, gem graders consider transparency, inclusions, and surface blemishes when evaluating clarity. Many gemstones contain inclusions, including virtually all diamonds. However, some are so small they don’t impact grading.

Inclusions in diamonds include things like minerals, some in crystal shapes and others in long needle shapes, and twinning wisps that form inside a stone. Gem cutters usually try to cut a piece of diamond rough to create a stone as free of inclusions as possible. Typically, inclusions can’t be removed, though some treatments try to minimize their impact in faceted gems.

Generally, the freer from inclusions, the more valuable the diamond. Nevertheless, geologists love inclusions in diamonds, since they reveal a lot about the Earth’s formation. (The youngest diamond is 900 million years old). Some inclusions can be quite beautiful and interesting, too. Diamonds can contain gems such as garnet or diopside and, often, even mini diamond crystals. In some cases, diamonds contain diamond inclusions that contain diamond inclusions! They all fit, one inside the other, like a Russian matryoshka doll. Included diamonds can make fascinating pieces for mineral or …

Phoebe Shang, GG

A gem lover and writer, Phoebe holds a graduate gemologist degree from the Gemological Institute of America and masters in writing from Columbia University. She got her start in gemology translating and editing Colored Stone and Mineral Highlights for a professor based in Shanghai. Whether in LA, Taipei, or New York, Phoebe spends her time searching for gems to design and being lost in good books.

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