One of the most important things to learn as you begin shopping for a diamond engagement ring is the distinction between carat weight and total carat weight. If you want to ensure you get a great return on your investment anyway.
From Carob to Carats
Despite popular belief, a carat is a density measurement rather than a weight measurement. The carob seed was used as a weighing method for valuable metals and gemstones for centuries.
This was because people assumed it was always the same size and weight. Despite the fact that this belief was obviously (to us) false, the practice was used well into the twentieth century. Today, one carat equals 200 milligrams. This "metric carat" was first used in 1907 and is currently the standard unit of measurement for jewels.
Any gemstone's weight is precise to 1/200th of a milligram. The standard for indicating the weight of a diamond is to round up to the next tenth of a carat, such as 0.6ct or 1.5ct.
A single carat is the weight of a single diamond. This weight is determined by the cut type, and the quality of the cut, as well as the diamond's size.
What is Total Carat Weight?
Unless it is a solitaire setting - ie a diamond engagement ring with just a single center stone - an engagement ring will usually have more than one diamond. This weight of these stones is frequently an estimate, especially when a ring with multiple tiny diamonds is appraised.
When the weight of these smaller diamonds is added to the weight of the main diamond, the total carat weight is calculated. Diamonds of this size, known as "melee diamonds," are not subjected to the same weighing procedure as larger stones.
To give the ring more prominence than it merits, the total carat weight is sometimes used. Small diamonds, for example, are used in pavé settings to increase visual appeal and “show off” the central diamond. Because they are frequently of lower quality than the central diamond, the total carat weight is not a reliable indicator of overall quality.
What Are Melee Diamonds?
Small diamonds under 0.15ct are referred to as melee. Rather than being the focal point of the ring, such stones serve to support a larger center stone. In general, melee diamonds will not be of exceptional quality.
Due to their small size, grading melee diamonds is exceptionally challenging. Even after grading, the price is likely to be far lower than a comparable quality bigger stone, carat for carat. A sieve method is used instead of weighing each individual stone. Melee diamonds are sieved together in baskets with ever larger pores. The residual diamonds are sieved through the next size up after the smallest have been sieved out. The process continues until all of the diamonds have been able to pass through a filter.
Each set of diamonds in a given "sieve size" will then be priced as if they were all the same weight, despite the minor changes in real size and weight.
Weighing Larger Diamonds - How It's Done
Grading and valuing diamonds gets easier once they are no longer in the melee size range. The cut type is easy to distinguish, and inclusions are easier to separate. It's also a lot simpler to tell how good a cut is and what color it is.
Furthermore, the diamond's weight becomes absolute. The weight is normally in half or quarter carats by the time we get to 3 carats. In practice, this means that a 3.4ct diamond will often cost the same as a 3.1ct diamond. The next increase is usually 3.5cts. Although some merchants price by the tenth of a carat, this is not standard practice.
Differentiating Between Carat Weight and Total Carat Weight
It isn't always the case that diamonds other than the center stone don't contribute to the overall weight or quality of the ring. Some rings, for example, will feature diamonds weighing more than 0.15 carats in addition to the main diamond. It does, however, necessitate caution when determining if the total carat weight of the diamonds in any setting is correct or whether you have all the necessary information.
Always look for the center stone's weight separately (assuming there is one).
If it isn't available, proceed with caution. It could indicate that the diamond has hidden damage or is of poorer quality.
Similarly, if more than one stone is present, a total carat weight should be supplied. If it isn't, you should know for insurance purposes, however it isn't as important as knowing the single diamond weight.