All diamonds contain natural traces of their growth history, these are called
inclusions. Inclusions can impede the passage of light through a diamond, thereby
affecting its sparkle. The GIA clarity scale reflects the number, type, size, location
and visibility of inclusions as seen under 10x magnification. The very best – and
rarest – clarity grade is flawless. Diamonds with inclusions that are not visible to
the unaided eye are more valuable than those with visible inclusions.