London Mayfair Grosvenor Diamonds

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Diamond Grading
“Rare fancy diamonds are the
ultimate high value and
tradable investment”

In order of rarity coloured diamonds are: red, green, blue, pink and yellow.

Carat, colour, clarity and cut are the four grading criteria used to classify and value diamonds.


Carat is the unit weight for all gemstones. One carat weight is divided into 100 ‘points’.


Rare stones of exceptional colour known as Fancies are graded as: Faint, Very Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark and Fancy Deep.


Clarity is determined by the number, nature, position, size and colour of internal characteristics called ‘inclusions’ and surface features called ‘blemishes’. Clarity is measured on a scale ranging from pure of flawless (F) to heavily included (I – 3).


Cut can add to a diamonds overall value. The ideal cut displays the brilliance and fire of the stone