Clarity is one of the four C’s of diamond grading, the others being carat, colour and cut. So what is clarity?

The term diamond clarity refers to how closely the stone approaches a perfect crystal. Almost all diamonds contain some small degree of “inclusions” – tiny amounts of non-crystal carbon or other minerals trapped within the stone. The inclusions, along with any general flaws and blemishes on or in the stone, reduce its clarity and brilliance and hence its value.

Diamonds are normally graded into one of six categories for clarity: Flawless (FL), Internally Flawless (IF), Very Very Slightly Included (VVS1 and VVS2), Very Slightly Included (VS1 and VS2), Slightly Included (SI1 and SI2) and Included (I1, I2 and I3). Note that minor inclusions are often invisible to the naked eye – diamonds are usually rated on their appearance under a magnification factor of ten.

Although inclusions are normally considered “bad” they do have one advantage: the pattern of inclusions can serve the equivalent of a diamond “fingerprint” to help in confirming the identity of a particular stone.