Diamond Inclusion Types Explained: What's Actually Inside Your Stone
TL;DR: Diamond inclusions fall into a handful of recognisable types — pinpoints, feathers, clouds, crystals, and needles being the most common — each affecting a stone's appearance and durability differently. Understanding what type of inclusion you're looking at matters more than the clarity grade alone when deciding if a stone is right for you.
Why Inclusion Type Matters More Than the Grade Alone
Two diamonds at the same clarity grade can look and behave differently depending on what kind of inclusion is present. A grade tells you how visible inclusions are overall; the type tells you whether they're likely to affect durability, how they'll interact with light, and whether they're the kind of thing your eye will actually be drawn to.
Pinpoints
Tiny crystal inclusions appearing as small dots, often clustered. The most common and least concerning inclusion type — they have no effect on durability and are typically invisible without magnification.
Feathers
Small internal fractures that can appear whitish or transparent depending on the angle. Most feathers are cosmetic and stable, but a feather reaching close to the surface is worth extra scrutiny, since it can theoretically extend under stress.
Clouds
Clusters of extremely tiny pinpoint inclusions so dense they create a hazy area rather than distinct points. Large or dense clouds can slightly reduce brilliance by scattering light, but small clouds are generally cosmetic only.
Crystals
Mineral inclusions of a different material trapped within the diamond during formation, sometimes visible as small dark or coloured specks. Purely cosmetic in almost all cases, with no durability impact.
Needles
Long, thin crystal inclusions. Generally cosmetic, though a needle reaching the surface (similar to a feather) is worth extra scrutiny.
What Actually Affects Durability
Feathers and needles that reach or come close to the surface are the inclusion types worth genuine attention — not because they're common problems, but because they're the ones that could theoretically extend under a hard impact. Pinpoints, clouds, and internal crystals are almost always purely cosmetic.
Choosing a Stone at À Vie Diamonds
We'll talk through the specific inclusion type and position on any stone you're considering, not just the clarity grade in isolation. Get in touch to discuss stone options.
Frequently Asked Questions
Which diamond inclusion type is most concerning? Feathers or needles that reach close to the surface, since they could theoretically extend under impact. Pinpoints, clouds, and crystals are almost always purely cosmetic.
Do inclusions affect how a diamond sparkles? Large or dense clouds can slightly reduce brilliance; most other inclusion types have no visible effect on light performance.
Last reviewed: July 2026 · À Vie Diamonds