The cut of a diamond determines the way light is returned from the diamond. This affects the brilliance, fire, and scintillation of a diamond.
Brilliance is the combination of all of the white light reflected from the surface and the inside of the a diamond.
Fire are flashes of color you see in a polished diamond.
Scintillation are flashes of light you see when the diamond, the light, or the observer moves
A diamond’s color is measured using the GIA® D-to-Z diamond color grading system. Essentially, the less color present, the higher the value of the diamond.
A diamond's clarity is graded on the absence of inclusions and blemishes.
Internal Characteristics = Inclusions
External Characteristics = Blemishes
FL, IF Diamond - Flawless: No internal or external flaws
VVS1, VVS2 Diamonds - Very, very slightly included: Very difficult to see inclusions under 10X magnification
VS1, VS2 Diamonds - Very, slightly included: Inclusions are not typically visible to the unaided eye
SI1, SI2 Diamonds - Slightly included: Inclusions are visible under 10X magnification and may be visible with the unaided eye
I1, I2, I3 Diamonds - Included: Inclusions are visible with the unaided eye
A diamond's price is directly influenced by its carat weight.
1 Carat = 200 milligrams
1 Point = 0.01 carat = 1/100 of a carat
Diamonds of equal weight are not necessarily the same size. Different proportions and depths will result in different size and weight combinations.