The color grading chart for diamonds starts at D (colorless), and proceeds downward steadily increasing in color to Z (light yellow). Anything past Z in the color scale is considered a fancy color, for example a canary yellow.
Most people do not know that diamonds come in every color. The most common are brown and yellow, however they come in beautiful shades of blue, pink, purple, red, green, and orange.
Below is an example of the GIA color grading scale.
In the scale above the colorless diamonds are going to be the most rare, and will therefore cost the most. When considering a color grade for a diamond you are purchasing, taking the type of metal it would be set in into account.
If the diamond is set in platinum or white gold, the yellow in the diamond will stand out more, conversely if the setting is in yellow gold it will deceive the eye into thinking the yellow is coming from the setting and not from the diamond.
Usually a “J” or higher color would not be noticeable after the diamond is set, however everyone perceives color differently so the best advice is to look at alot of different color diamonds and determine where you can no longer see the difference.
Of course clarity is my favorite of the four “C’s”. However you probably don’t want any massive eye visible inclusions in your diamond. An inclusion is any imperfection in the diamond, and can fall into two categories.
An internal clarity characteristic is anything within the diamond, for example an included crystal, feather, or a pinpoint.
An external clarity characteristic is anything on the surface of the diamond, for example a scratch, cavity, or a chip.
Below is an example of the GIA clarity grading scale.
In the scale above Flawless (FL) and Internally Flawless (IF) are the most rare, and will therefore cost the most. When considering a clarity grade for a diamond you are purchasing, keep in mind the following;
• Above VS1 the chances of the average customer even being able to find the inclusions under magnification are low.
• Even though the I1 clarity grade is listed as imperfect, they do not always have eye visible inclusions and will be priced much lower than SI2’s.
• Color is much more important when buying a diamond than clarity. Color is graded to the bare eye where clarity is only graded under magnification.
Carat weight is the physical weight of the diamond. A carat is a very light unit of measurement, a carat is only the equivalent of 1/5 of a gram. As you gathered in the cut tutorial, carat weight does not necessarily reflect the size of the diamond.
Carat weight is weighed out to the thousandth of a carat and is rounded to the hundredth of a carat. For example, if a diamond weighs 0.998 the carat weight would be 1.00, however if the diamond weighed 0.992 the diamond weight would be adjusted to 0.99.
There are certain carat weights that will raise the price of the diamond. For example a 0.95 carat diamond will cost a couple of thousand dollars less than a similar quality diamond that weighs 1.00 carat. This is why diamond cutters make sure that they hit those magic marks.