Clarity of diamond color
Diamonds are graded using various qualities, diamond color and clarity being one of the major factors. Diamonds are graded on a scale of D (a colorless diamond) through to Z (lightly colored diamond). Other colored diamonds containing yellows, blues or pinks are graded by a separate diamond color chart
GIA, who grade most of the diamonds sold in the world today is the largest, oldest and most respected laboratories in the world, they issue certifications for diamonds in the form of a Grading Reports. GIA is a non-profit organization and is not owned or ran by diamond retailers or wholesalers. The GIA adeveloped the "four Cs" diamond rating system which is used almost universally today.