Diamond question

its another way to measure a diamond - i think 100 points = 1 carat i think?

Tips on Choosing a Diamond Size

Diamonds are sold according to weight, which is measured in carats* and points. To illustrate, think of this: when you buy bananas at the grocery store, they are put on a scale and sold to you by weight, and that weight is pounds and ounces. Diamonds are sold the same way; they are put on a scale and sold by weight, but that weight is carats and points.

A carat is subdivided into 100 points, so a diamond weighing 75 points is a ¾-carat diamond, 33 points is 1/3-carat, 150 points is a 1.5 carat, and so on. Points are not to be confused with facets, however, which are the cut surfaces of the diamond.

Points are measured within ranges, so that a ¾ carat diamond may be between 69 and 82 points and still be considered a ¾ carat. Note the table below.


Fraction Points Approximate mm width
(round diamonds)
1/4 carat
= .23 - .28
4.1
1/3 carat = .29 - .36 4.4
3/8 carat = .37 - .44 4.8
1/2 carat = .45 - .58 5.2
5/8 carat = .59 - .68 5.5
3/4 carat = .69 - .82 5.8
7/8 carat = .83 - .94 6.2
1.0 carat = .95 - 1.05 6.5


Diamonds are most accurately weighed when they are not mounted in a setting. In fact, most gemological laboratories will only grade “loose” diamonds—meaning, diamonds that are unmounted. If other factors are equal, the more a stone weighs, the more valuable it will be. Note in the image below that a 2-carat diamond does not appear to be twice the size of a 1-carat diamond when viewed from the top.

Move your mouse over the different diamond sizes below to get an idea of how each size appears.