Cut - What is the proportion of the diamond? Round brilliant diamonds are commonly cut 58 facets. The better proportioned these facets, the more light will be reflected to the viewer's eye. When cut properly, the diamond will sparkle more. Diamond cuts are measured by the percentage table, so always ask for it. A good table percentage is between 55-60%.
Carat - How big is the diamond? Larger diamonds often cost more per carat due to their size. There are 100 points to a carat; hence a 50 point diamond is 1/2 carat. Always get the actual point size of the diamond rather than a fractional weight. Sometimes jewelers will try to sell a .90 diamond as a 1 carat diamond.
Clarity - How clear is the stone? Clarity ranges from flawless (perfect) to I (included).
Flawless: perfect inside and out
Internally Flawless: may have minor blemishes on the outside
VVS1, VVS2: have very very small inclusions
VS1, VS2: Have very small inclusions
SI1, SI2, SI3: have small inclusions
I1, I2, I3: have inclusions visible to the naked eye
Color - Diamond colors generally range from D-X for white and yellow diamonds, with D being the whitest. Around S they become fancy yellow diamonds.
