Natural diamonds are formed in the environment of high temperature and high pressure on the earth, and the origin and composition are different, each diamond will have different inclusions.
Basically, the surface defects are invisible to the naked eye. Jewellers or appraisers need to use a 10x magnifying glass to identify according to the size, type, position, colour or visibility of diamonds, and call the inside of diamonds as inclusions, and the surface of diamonds as surface features.
According to the clarity of GIA diamond, it can be divided into 11 grades, based on 10x magnifying glass.
Flawless (FL)- diamonds have no inclusions or surface features.
Internally Flawless (IF) - no visible inclusions, only visible surface features, which can only be seen by professional graders.
Very, Very Slightly Included (VVS1 and VVS2) - it is difficult for even a professional grader to see the inclusions.
Very Slightly Included (VS1 and VS2) - small inclusions ranging from difficult to see by professional graders to easier to see
Slightly Included (SI1 and SI2)- the inclusion can be seen by a professional grader
Included (I1, I2 and I3)- inclusions are clearly visible in the and may affect transparency and brightness.
The figure below shows a GIA certificate, which can be illustrated in the lower right corner to indicate the location of the contents.
