  
CARAT:
The Larger a Diamond, the More Rare
Larger diamonds are found relatively infrequently in nature, which places them at the rarist level of the Diamond Quality Pyramid. What also makes a bigger diamond so desirable is that it shows off a stone's fine color and cut, and therefore its brilliance, to its best advantage.
A diamond's size is measured in carat weight, and each carat is equal to 100 points. A .75 carat diamond is the same as a 75-point diamond or a 3/4 carat stone.
While larger diamonds are highly prized, diamonds of equal size may vary widely in value and brilliance, depending on their qualities of clarity, cut, and color.
| Diamond Size | | Actual Diamond Weight |
| 1/4 ct. | = | .22-.28 |
| 1/3 ct. | = | .29-.36 |
| 3/8 ct. | = | .37-.44 |
| 1/2 ct. | = | .45-.65 |
| 3/4 ct. | = | .66-.89 |
| 1.00 ct. | = | .90- 1.18 |
| 1.25 ct. | = | 1.19- 1.39 |
| 1.50 ct. | = | 1.40- 1.89 |
| 2.00 ct. | = | 1.90-2.39 |
| 2.5 ct. | = | 2.40-2.65 |
| 3.00 ct. | = | 3.00+ |
|