The 4 C's
The cut of a diamond is referring to how light is returned due to a diamonds facets. It is responsible for brilliance, fire, and scintillation.
Brilliance is the combination of all the white light reflected from the surface and the inside of a diamond.
Fire refers to the flashes of color you see in a diamond.
Scintillation are flashes of the light seen when the wearer moves or color shifts.
The color of a diamond is determined by using the GIA® D-to-Z color grading system which is the most widely accepted for grading.
Diamonds are evaluated based on the absence of color. So no hue equals a higher value.
A diamonds clarity is graded on the absence of inclusions and
blemishes. Inclusions are internal characteristics and blemishes are
Fl/IF: Flawless, there are no internal or external flaws.
VVS1/VVS2: Very, Very slightly included. Inclusions not visible to the eye and are difficult to see even under 10x magnification.
VS1/VS1: Very, slightly included. Inclusions are typically not visible to the naked eye.
SI1/SI2: Slightly included. Inclusions are visible under 10x magnification and may be visible to the naked eye.
I1/I2/I3: Included. Inclusions are visible to the naked eye.
Carat weight also links to the price of the diamond.
Diamonds of equal carat weight are not always the same size.
Different proportions and depths will result in different size and weight combinations.
Shape also plays a factor in pricing, this is because with certain shapes the supply is low and the demand is high, where with other it's opposite. This can change regularly.