Diamonds are crystallised carbon, during their formation traces of non- crystallised materials were able to be trapped within it. These imperfections are called inclusions and can be measured (microns).

These inclusions can be of various colours, transparent (gaseous bubble), black (carbon), green, brown etc.

Some are more obvious to the eye than others, this factor is taken into consideration where grading diamonds is concerned.

If an imperfection is too large or too coloured it can interfere with the brilliance or sparkle of the diamond.

Clarity is determined by examination under a specially adapted stereoscopic microscope, the norm being that the grading is labelled as 'viewed under 10x magnification by a trained eye using a loupe free of chromatic aberation'.

The size of the imperfections go from 'Flawless'(IF or F) to 'P3'(pique) or 'I3'(inclusion3).