Diamonds are a form of the element carbon with a crystal structure. Diamond's great hardness relative to other materials has been known since antiquity, and is the source of its name derived from the ancient Greek ἀδάμας that means "unbreakable".
Diamonds are the hardest natural substance on earth and rate a 10 on the Mohs Hardness Scale. Diamond is also known as April's birthstone. They are thought to be first recognized and mined in India many centuries ago.
Four characteristics, known informally as the "Four Cs", are now commonly used as the basic descriptors of diamonds: Carat, Clarity, Color and Cut.
This system was developed by GIA (Gemological Institute of America), one of the major gemological associations internationally recognized to evaluate diamond characteristics.
The carat weight measures the mass of a diamond and the clarity is a measure of internal defects of a diamond called inclusions.
GIA’s D-to-Z diamond color-grading system measures the degree of colorlessness: the finest quality as per color grading is totally colorless, which is graded as D color diamond across the globe, meaning it is absolutely free from any color.
Last, the cut of a diamond describes the quality of workmanship and the angles to which a diamond is cut.