A diamond's clarity is determined by the degree to which it is free from naturally occurring inclusions often called 'nature's fingerprints'.

Blue correction (inclusion and magnification)

The number, type, colour , size and position of the internal birthmarks can affect a diamond's value. However, many are invisible to the naked eye requiring magnification under a standard 10x magnification loupe before the become apparent. The fewer the inclusions, the rarer the stone.