In the diamond industry, a point is a unit of weight used to measure diamonds and other gemstones. One point is equal to one hundredth (1/100) of a carat, or 0.01 carats.
Understanding Points in Diamond Weight
Diamonds are weighed in carats (ct), with each carat divided into 100 points. This system allows for precise measurements, especially for smaller diamonds.
For example:
A 15-point diamond weighs 0.15 carats and is sometimes referred to as a “fifteen-pointer.”
A 50-point diamond weighs 0.50 carats, also called a “half-carat” diamond.
A 100-point diamond equals 1.00 carat, making it a one-carat diamond.
Why Points Matter
Precision – Points allow for highly accurate diamond weight measurement, especially for small diamonds where even minor differences in weight can affect value.
Pricing – Since diamond prices are calculated per carat, even a small difference in weight (e.g., 0.49 ct vs. 0.50 ct) can significantly impact the price.
Common Usage – Jewelers and gemologists frequently use the term “points” when referring to diamonds under one carat, as it simplifies communication of weight.
Example Diamond Sizes in Points
Points Carats Common Name
10 pts 0.10 ct Ten-pointer
25 pts 0.25 ct Quarter-carat
50 pts 0.50 ct Half-carat
75 pts 0.75 ct Three-quarter carat
100 pts 1.00 ct One-carat
While points are commonly used for diamonds below 1.00 carat, larger diamonds are generally described in carats rather than points (e.g., a 1.25-carat diamond rather than a 125-pointer).
The point system is an essential part of diamond grading and pricing, providing precise measurements that ensure accuracy in weight calculation. Whether buying or selling a diamond, understanding points can help in making informed decisions about size, value, and pricing.