The carat of a loose diamond is its main price determinant, although cut, clarity, and color of the gem also contribute to the cost. Carat is a diamond’s weight, although it is often interchangeably used to refer to its size. In fact, the diameter of the stone is a more precise determinant of its size and not the weight of the stone.
Diamond size is measured in millimeters considering length, width, as well as depth; the first two measurements form the top part of the gemstone. In round diamonds, the length and width of the stone will be extremely close. However, in fancy cut diamonds, they will deviate depending on the extent of elongation.
The depth alludes to the distance from a diamond’s top surface, called crown, to its bottom point, called cullet. This measure plays a significant role in evaluating the diamond cut, but cannot be considered to evaluate how big a stone is when the diamond is set in a metal ring.
Weight vs. Size
The difference between weight and size becomes the most significant factor when buyers evaluate many diamonds that look similar. Take the example of two round shaped gemstones of Excellent cut, VS-2 clarity, G-color, and the same per carat price. If one of the gems weighs 1.00 carat, and the other weighs 1.05 carat, the second one will be a bit pricier in comparison.
It is also possible for the diameter of the said diamonds to be the same. Like, for instance, the diameter of both stones can be 6.5 millimeters, and the one weighing 1.05 carat is a bit deeper in terms of depth. That would account for the additional 0.05 carat weight even as the diameter remains the same in both. If so, the customer would end up paying around five percent more for a diamond ring with the exact appearance as the one weighing 1.00 carat. In fact, this goes true for diamonds of all shapes.
The ideally followed approach to make the most of a loose diamond is to use its carat weight as a common guide while purchasing it. However, once you start ranking the loose diamonds to select the one within your budget, you would want to contrast them using its dimensions rather than merely looking at the carat weight. This is even more so because a diamond’s per-carat-price is influenced by its size, and not just its carat weight.