Nature is rarely perfect and as diamonds are formed in the earth over billions of years, there will inevitably be imperfections as carbon crystallises to become a diamond. These imperfections of crystallisation, which occur in the diamond, are known as ‘inclusions’. The presence of imperfections, or a stone's clarity, is a large component of assessing the value of diamonds. While diamond jewellery buyers can see imperfections that appear as small cracks or miniscule flecks of black carbon with an eye scope, these blemishes often can't be seen with the naked eye.
There are many types of inclusions that can occur within a diamond. A ‘Feather’ is an inclusion that gives the impression that part of the internal gem is ‘chipped’. This is also known as a ‘Beauty Spot’. There may also be black dots and lines throughout the diamond, which is simply uncrystallised carbon. These are known as ‘Specks’ and ‘Hair Lines’. The type, number, size and position of the inclusions determine the clarity of a diamond and as long as they do not affect the passage of light through the diamond inclusions often will not detract from its beauty. Often the subtle location of an inclusion can mean that it will have no effect on the look of a diamond at all. A ‘flawless’ diamond is not necessarily a perfect diamond. It only means that no imperfections are visible to a trained eye, using 10 x magnifications in good light. The chart below is used to grade a diamond based on its imperfection.