Do inclusions make a gemstone less valuable?

Generally yes, because more visible inclusions affect the stone's clarity grade and its appearance. But the impact depends heavily on the type of stone. Diamonds are graded on a strict clarity scale where visible inclusions reduce value significantly, while emeralds are almost always included and priced with that in mind, so a clean emerald commands a very large premium.

Can you see inclusions in a diamond with the naked eye?

In a well-cut diamond of SI1 clarity or above, most inclusions are very difficult to spot without magnification. Below that, at SI2 and I grades, inclusions may be visible to the naked eye. The GIA clarity scale runs from Flawless down to I3, and for most people eye-clean stones at VS or SI grades offer good value.

Are inclusions ever a good thing?

Yes, sometimes. In moss agate, rutilated quartz and tourmalined quartz, the inclusions are the whole point of the stone's appeal, creating the patterns and colour that make them beautiful. In natural rubies and sapphires, certain inclusions like silk are a sign of natural origin rather than a defect.

What is an inclusion in a gemstone?

By Jared James · Last updated 21 May 2026

Definition

An inclusion is any internal characteristic trapped within a gemstone during its formation, including tiny crystals of other minerals, small fractures called feathers, cloud-like clusters of minute cavities, or irregular growth patterns. Inclusions form naturally as the stone grows under heat and pressure, so every natural gemstone has them to some degree. In diamonds they are a key factor in determining clarity grade, and in coloured stones they are often accepted and even appreciated as proof of natural origin and as marks that make each stone unique.

Frequently asked questions

Do inclusions make a gemstone less valuable?: Generally yes, because more visible inclusions affect the stone's clarity grade and its appearance. But the impact depends heavily on the type of stone. Diamonds are graded on a strict clarity scale where visible inclusions reduce value significantly, while emeralds are almost always included and priced with that in mind, so a clean emerald commands a very large premium.
Can you see inclusions in a diamond with the naked eye?: In a well-cut diamond of SI1 clarity or above, most inclusions are very difficult to spot without magnification. Below that, at SI2 and I grades, inclusions may be visible to the naked eye. The GIA clarity scale runs from Flawless down to I3, and for most people eye-clean stones at VS or SI grades offer good value.
Are inclusions ever a good thing?: Yes, sometimes. In moss agate, rutilated quartz and tourmalined quartz, the inclusions are the whole point of the stone's appeal, creating the patterns and colour that make them beautiful. In natural rubies and sapphires, certain inclusions like silk are a sign of natural origin rather than a defect.

Designing a ring

Talk through inclusion with us

Tell us what you have in mind, even if it is only a budget and a piece of jewellery type, and we will help you weigh up the options. We reply to every enquiry, usually within one business day.

Contact the studio

Related terms

Clarity

Imperfection

Blemish

Frequently asked questions

Talk through inclusion with us