Diamond Clarity

As you might expect, clarity refers to how clear a diamond is. It is common for diamonds to have inner flaws, and it is the visibility and size of these imperfections that affects the clearness of the stone. But exactly what is clarity, how can it be measured and how will it affect the quality of the jewel?

Diamonds are crystals of carbon, naturally formed under extreme pressures and intense temperatures at depths of between 130 and 200 kilometres beneath the Earth’s surface. Geological activity then forces the diamonds up through volcanic pipes, making it possible for the stones to be mined from the surface.

During the process of formation, internal characteristics develop within the stones. These features are commonly referred to as inclusions and they can include clouds, feathers, knots, cavities, cleavage and more. As well as internal features, diamonds can have exterior irregularities known as blemishes, which can occur either naturally or during the cutting process. These include scratches, nicks and areas of the original crystal face left on the surface of the cut stone. Fracture filling and adding extra facets are tactics commonly employed to improve the brilliance of the finished stones, but these procedures must be carried out by a skilled craftsman if mistakes are to be avoided. For example, adding too much filling can have a negative impact and reduce the clarity of a diamond.

While inclusions can be beneficial in terms of helping scientists to identify and draw information from individual stones, the number and type of flaws a diamond has can lower its quality and value. The fewer blemishes a diamond has, the more brilliantly clear it will appear and the more desirable it will be in the jewellery market.

For a more in depth explanation, take a look at our diamond clarity chart:

Internally flawless Very, very small inclusions, very hard to locate under 10x magnification, and not visible to the unaided eye. Very small inclusions, difficult to locate under 10x magnification, and not visible to the unaided eye.
Small inclusions, relatively easy to locate under 10x magnification, but not seen with the unaided eye. Piqué (inclusions visible to unaided eye)


It is common for diamonds to include flaws. In fact, it is extremely rare to find gemstones that have no imperfections at all. Because of its rarity, a flawless jewel can set a buyer back a very large sum of money. Conversely, gems that have inclusions which are visible to the naked eye are significantly cheaper. It is, however, easy to find a quality diamond without having to break the bank, as the majority of jewels available on the market fall between these two extremes. Small inclusions, which are only visible when examined under magnification of 10x, are highly sought-after as they have a beautiful clear appearance while remaining at an affordable price.

When making a jewellery purchase, we recommend that you take a look at our diamond clarity scale to ensure that you are getting the best possible grade for your personal taste and budget.  

If you still feel that you need additional advice after reading this diamond clarity guide, why not speak to one of our expert consultants here at Marlow’s? Our team of experience diamond specialists can provide you with all the information you require concerning clarity and they can offer advice on how to take care of your precious stone to ensure it remains in sparkling condition for years to come

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