Natural diamonds have been created by extreme heat and pressure deep within the earth, millions, and even billions, of years ago. This organic process means that just about all diamonds contain internal features, for example traces of minerals or uncrystallised carbon, called inclusions. Clarity refers to a diamond’s natural inclusions.
Even when invisible to the naked eye, inclusions and blemishes can still influence the way light is reflected and refracted, which is why their shape, size and position is taken into account in diamond grading reports. Diamonds with fewer of these characteristics are deemed to have a higher clarity, ranging from the very rare FL (flawless internally and externally) to I, signalling a number of more significant inclusions and blemishes. As the 4Cs all influence each other to some extent, characteristics of diamond clarity can be balanced by those of colour when you are choosing your diamond.
At De Beers, we only choose white diamonds up until the grade SI2, meaning that their inclusions are not actually visible to the naked eye, but only under magnification. These inclusions don’t affect the structural stability of a diamond.