There are many different labs around the world that certify diamonds. The most widely used is G.I.A (Gemological Institute of America). All engagement ring diamonds we sell come with a GIA certificate. The certificate gives you all of the information about the diamond as well as a map of the inclusions.
There are 2 categories of shapes:
Round and fancy shape. Any other shape thats not round is considered a fancy shape. On a round diamond, things like the cut and symmetry is really important. A fancy shape diamond is not symmetrical the same way a round is, therefore it is much harder to get an excellent cut grade on a fancy shape.
THE 4 C'S:
As you go down in letters, each letter will have slightly more yellow. In certain shapes you can see this more than others. From D to J, the color is only seen in the pavilion (back) of the diamond. From K to Z, you can see the color more and more face up.
Once you go past Z, you are in the fancy colored diamond section, which is different.
Inclusions come in different shapes and colors. They are other substances that formed when the diamond formed in the earth. They can be clear, white, brown, black, or even red (ruby). Up to SI2 - you can have stones that are eye-clean meaning that the inclusions cannot be seen to the naked eye (only under a 10x magnified loop or more). There are also stones that are not eye-clean.
The table below shows the G.I.A clarity scale:
The cut is a lot more important than most people think. There are actually 3 different factors that determine the overall cut grade a diamond gets: cut, polish, and symmetry; however the polish and symmetry also get its own individual cut grade. The cut of the diamond determines how the light goes in and out of the diamond - meaning how much it sparkles. The rainbow colors that you see when you move a diamond under light is what we call "fire" and that is one factor of cut. A lot of other factors go into cut such as the table and depth. Depth is very important because it determines partially where the weight of the diamond is. You can have 2 stones that both weigh 1 carat but if one has a high depth, a lot of the weight can be in the bottom of the stone and therefore that stone will look smaller.
The table below shows the different G.I.A cut grades that a diamond can have:
The carat is the one that most people know. It is the weight of the diamond. However, the carat size is not the only thing that determines how big a diamond looks. Other factors such as table size and depth play a part. The measurements of a diamond is what actually determines how big the diamond looks.
In addition, anything under 1 carat, we refer to as 'pointers' so a half carat diamond or .50 carats is also known as 50 pointers. 100 points = 1 carat. When we say 1.20 carats, that means its 1 carat and 20 points.