Glossary
Clarity type (I, II, III)
Because each gem species grows differently, GIA assigns coloured gemstones to three clarity types. Type I usually grows very clean (for example aquamarine). Type II usually shows some inclusions – ruby, sapphire and alexandrite belong here. Type III is almost always noticeably included, such as emerald. A stone’s clarity is therefore always judged relative to its type.
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- Laboratory reportsUnderstanding a laboratory reportA laboratory report is a gemstone's most important document. Which information it contains, how to read it and what it does not say.Read more
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Updated 2026-10-06