The 4 Cs: Clarity

Posted on the 10th November 2016

Definition of clarity: refers to the purity of the gemstone ie. the presence of inclusions in a gem material

Diamonds: There is an internationally recognised scale to which they are graded ie. GIA grading, flawless, IF etc

Coloured Gemstones: There is no international standard for grading clarity as some inclusions in coloured gemstones are seen as desirable as long as they do not detract from the beauty of the gemstone.

For example, silk in sapphire and horsetail inclusions in demantoid garnets are much sought after.

Some coloured gemstones have inclusions which are the main feature, for example quartz with inclusions of rutile or needles within tourmalines.

From a gemmologist’s point of view, finding inclusions can help with identifying the nature of the gemstone. Some inclusions are indicative of a synthetic or simulant. Other distinctive inclusions aid with identifying a stone as natural, some can even help to pinpoint the origin of the gem.

Of the 4 Cs, generally colour is the most important factor for coloured gemstones, read more about colour.