1: Diamond Carat Weight
Diamonds are weighed in metric carats. A carat is made up of 100 points, so a 50 point diamond weighs 0.50ct. The weight of a diamond can usually dictate the size of the stone.
2: Diamond Clarity
When diamonds are formed in the earth under extreme heat and pressure, they often show natural characteristics, either external (known as blemishes) or internal (known as inclusions). Diamonds are graded according to how visible these characteristics are:
Flawless (F) - No blemishes or inclusions are visible, even under 10x magnification.
Internally Flawless (IF) - No inclusions and only minor blemishes are visible in the diamond, even under 10x magnification.
Very, Very Slightly Included (VVS1, VVS2) - Inclusions are very difficult to see under 10x magnification.
Very Slightly Included (VS1, VS2) - Inclusions are minor and difficult to see under 10x magnification.
Slightly Included (SI1, SI2) - Inclusions are visible under 10x magnification yet difficult to see with the naked eye.
Included (I1, I2, I3 - also known as P1, P2, P3) - Inclusions are visible to the naked eye.
3: Diamond Colour
Diamonds are graded by how colourless they are. Fancy coloured diamonds, such as pink, orange, blue etc., fall outside of this scale. The scale goes from D - Z, from colourless to light yellow or brown.
D - F - Colourless
G - J - Near colourless
K - M - Faint
N - R - Very light
S - Z - Light
4: Diamond Cut
A round brilliant diamond is graded on how it has been cut. This refers to the proportions of the diamond which lets light get reflected through the stone to make it sparkle. When a diamond has a lower cut grade, the diamond appears more dull. Only round brilliant diamonds will have a cut grade. The diamond is graded as:
Cut and shape are often used interchangeably. The shape refers to the physical outline of the stone such as a princess cut, oval, pear, etc. Round brilliant diamonds are the most popular shape. Any diamond that is not a round brilliant is known as a fancy shape.