The 4C’s of diamonds refer to characteristics that maximize the beauty and of a diamond. The 4C’s are cut, color, clarity, and carat.
Cut describes the silhouette or form created by a diamond’s contours and facets. Shapes vary from round to fancy cuts, such as emerald, pear, and princess. Style includes variations of brilliant, stepped, and mixed cuts. Beautiful diamonds can be found in virtually any shape or style.
Color refers to the natural color of a diamond and not the colors that reflects when a diamond moves. Diamonds with less color allow more light to pass. This gives the diamond more intensity.
For colorless to light diamonds, color is graded on a scale from “D” (colorless) to “Z” (possessing a strong tonal modifier). Most diamonds have a yellow or brown tonal modifier.
Clarity refers to the internal and external characteristics, or inclusions, in a diamond. Inclusions are what gemologists often call internal characteristics and it is what gives a natural diamond character. Diamonds that have the fewest and smallest inclusions have the highest clarity grades and also the highest price. External characteristics are called blemishes.
The diamond clarity ranges from Flawless to Included
Flawless - The diamond have zero visible inclusions or surface blemishes at 10x magnification.
Internally Flawless - No visible internal characteristics at 10x magnification, but may have minor surface blemishes
Very Very Slightly Included - Diamonds with very, very small inclusions that are difficult to see at 10x magnification.
Very Slightly Included - Diamonds with very small inclusions that are difficult to somewhat easy to see at 10x magnification.
SI1, SI2, SI3
Slightly Included - Diamonds that have small inclusions that are easy or very easy to see at 10x magnification. Occasionally, visible to the eye.
I1, I2, I3
Included - Diamonds that have medium or large inclusions that are obvious to the eye.
A carat is a unit of metric measurement used for gems. One carat (ct.) equals 100 points, 200 milligrams, or 1/5 of a gram. A common misunderstanding is that the carat refers to the size of diamond. The carat refers to a diamond's weight and not the size of the stone. And while a big rock can be a status symbol it does not always mean that a larger carat weight is better than a smaller carat weight, a big carat weight does not mean that the diamond has an amazing sparkle. The sparkle comes from the cut of the diamond. Which means that a 1 carat diamond can have a more beautiful sparkle, than a diamond with 3 carat weight.