Diamond Inclusions & Blemishes

Let’s take a look at some of the different types of blemishes and inclusions that can appear on the diamond and consequently impact the clarity of it.


Let’s begin with one of the most problematic flaws; knots. A knot appears on the surface of the diamond. They tend to be visible to the naked eye, and thus a low clarity grading is to be expected

Mineral inclusions or crystals

The majority of diamonds will have minute minerals or crystals imbedded inside, although these will not usually be visible to the naked eye. These can be fragments of the likes of olivine, calcite, diopside, garnet, or silica. In some cases, they can even be other little diamonds.

Twinning wisps

During the stone’s original growth, the crystal may have entwined into a trail, and this is known as twinning wisps.


As you may have gathered by the name, these inclusions look like a feather. This is the term used to describe cracks within the stone. Small cracks under the surface aren’t usually an issue. But, those close to the surface can cause huge problems, especially in terms of durability.


This relates to very small dark or light crystals in the diamond.

Pinpoint clouds

Pinpoint clouds are a cluster of the former, and can result in a cloudy area on the diamond.


A needle can appear as a streak of light within the stone. They are long inclusions in the shape of a needle, and they can be particularly damaging to clarity when they are in clusters.

Indented natural

An indented natural can be left by the cutter because they are their guide for ensuring they get the maximum weight from the rough diamond.

Diamond Inclusions & Blemishes