Not to be confused with "size"
- Carat is the most misunderstood of the 4Cs. It actually refers to a diamond's weight, not its size. The size is referred to in a different unit of measurement, by milometers (mm).
- A metric "carat" is defined as 200 milligrams. Each carat can be subdivided into 100 points. This allows very precise measurements to the hundredth decimal place. So you will often hear a jewellery professional refer to a diamond in points, example: 0.25ct would be said as 25 points.
- Consider cut and carat together; a larger carat diamond with a poor cut grade can appear smaller than a smaller diamond with a higher cut grade.
- A trick to maximize your budget, "Buy Shy," which means selecting a carat weight slightly below the whole and half carat marks. For example, instead of a 2.0-carat diamond, consider buying a 1.9-carat weight. This will save a considerable amount of money and the slight size difference will never be noticed.
All else being equal, price increases with carat weight, because large diamonds are more rare and more desirable. Two diamonds of equal carat weight can have very different values (and prices) depending on the three other 4C's.
Some tips from the experts when picking a diamond:
- If a large carat weight is important to you, yet you're working within a strict budget, consider a diamond with a good cut, SI1-SI2 clarity, and an I or J colour grade.
- Diamond prices jump at the full-, half- and quarter- carat weights. Diamonds just below these weights cost significantly less, and, because carat weight is distributed across the entirety of the diamond, small size differences are almost impossible to detect.
- Keep in mind that the smaller the finger, the larger the diamond will appear. A 1.5-carat diamond solitaire looks much larger on a size 4 finger than a size 8