Carat - weight of loose or certified diamonds is measured in carats.

Dimensions of the loose or certified diamonds should not be confused with carat weight. Why is it unrelated? Because a stone could have varying depths therefore some could appear bigger depending on the cut.

The size of a loose or certified diamonds has the biggest impact on its price. The metric carat, which equals 0.20 gram, is the standard unit of weight for loose or certified diamonds and most other gems. If other factors are equal, the more a stone weighs, the more valuable it will be.

Here are several ways to express 1 carat:

1 ct.
200 milligrams
1/5 gram
100 points
4 grainer (not often used in retail environment)

Point to remember: Size and colour are immediately apparent.

Next - Diamond Colour