4Cs:
Carat: Weight given in carats, recorded to the nearest hundredth of a carat. One carat is equal to 1/5 of a gram.
Colour: The absence of color ranging from D (colourless) to Z (light yellow or brown).
Clarity: The relative absence of inclusions and blemishes. Graded on a scale from Flawless to Included.
Cut Grade: Cut grade incorporates the aspects of face-up appearance, design, and craftsmanship.