International Gem Assessment Inc | Diamonds - 4C's
The 4C's of Diamond Grading
Every diamond is unique. Each reflects the story of its arduous journey from deep inside the earth to a cherished object of adornment. Yet all diamonds share certain features that allow us to compare and evaluate them. These features are called the 4Cs.
Carat
A diamond's weight is expressed in Carats. Each carat is divided into 100 points, which means that a 1 Carat stone equals 100 points. Another example shows half of a carat written as 0.50 CT. Some dealers will advertise a ring as 1.00 CTW, which means that all of the stones total one carat.
Clarity
Thanks to nature, each diamond has its own characteristics. Many factors, including inclusions and blemishes, along with their size, colour and position, help us to determine a clarity grade. The difference between inclusion and a blemish is that inclusion is positioned within the stone, while a blemish is on the surface.
Colour
Colourless diamonds are the rarest. Most diamonds have slight shades of yellow or brown. the GIA (Gemological Institute of America) colour grading system uses the letters D through Z.
Cut
The cut is the only characteristic of a diamond derived from a human element. The cut is what gives a diamond its brilliance and fire.
