Carat Weight

The common unit of weight measurement of diamonds (and most other gem stones) is a carat, equal to precisely 0.02 grams. The name of this unit comes from the name of carob fruits, the seeds of which were used for measuring the weight of small items in the past. Sometimes the size is described in points, which are simply 1/100 carats. Unlike all the other properties of a faceted diamond weight is a purely objective property, which makes it the easiest to understand and measure. Ironically it is also the least important. A large stone may be viewed by some as a status symbol, but such a notion often neglects the fact that a diamond whose only virtue is its size will look no different than a piece of glass. A well cut diamond on the other hand, will attract attention both across a crowded room and up close with its powerful flashes of light and brilliance.

While choosing the size of the diamond is a personal decision, different factors have to be taken into account when considering larger diamonds as opposed to smaller ones. One of them is that the colour is more pronounced in larger diamonds. Diamonds under 1 carat with a colour grade H will look almost white, however a 5 carat stone with the same grade will have an unmistakable yellow tint.

An interesting phenomenon revolves around the fact that the per carat prices of diamonds are dependant on their weight and the price jumps at certain sizes. Sizes of 0.5, 1.0, 1.5 carats and so on are substantially more expensive than 0.49, 0.99, 1.49 carats. This goes against common sense since 0.99 and 1.00 carat stones have no visual difference. Two diamonds have to be considerably different in weight to appear to be somewhat different in size, since a lot of weight goes to increase the depth of the stone, while visual size is only appraised based on the size of the table. You probably would not tell a difference even between 0.95 and 1.05 carats, but the difference in price can be 20-25%.

From the same principle, you are much more likely to get a substandard cut if you choose a 1.00 carat stone as apposed to slightly below or above the specific weight point, since cutters are more inclined to leave some extra dead weight on the stone to make it more expensive. Dead weight detracts from the beauty of the stone.

In contrast to diamonds with excess weight, some diamonds are cut too flat, resulting in a stone that looks spread out and larger than an ideally cut diamond of the same weight. This is usually done when the rough stone has an unusually small depth. Regardless of the stone being too deep or too shallow, its optical performance will be compromised.

When looking at really large diamonds, in excess of 5 carats, the prices go up exponentially. About 50% of the weight of the rough is lost during cutting and faceting, so very large stones are also increasingly more rare, which affects the price. Large diamonds are almost never cut by low cost outsourced cutters, since quality cut is very valuable for large stones, and this means the cost of simply cutting a large diamond is very high.

Most diamonds sold online from reputable sources will cite the exact measurements not only in carats, but also in millimeters that will allow you to compare different diamonds by weight as well as by visual size. This will ensure that you get a diamond that has not only the carats, but also the sparkle.

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