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Carat: How the weight of a diamond affects its value

Published : 2018-03-04 13:54:03
Categories : Diamond

One of the 8 criteria of diamond quality is its weight. The unit of measurement for the weight of a diamond is the carat.

What is a carat?

A carat is the equivalent of a weight of 0.20 gram. There are 100 points in a carat. Therefore, a 50-point diamond is a diamond of half a carat and weighs 0.10 gram. A point represents one hundredth of a carat, and weighs 0.02 gram. The carat is divided into 100 points to define small diamonds : for example, a quarter diamond will be called "25 points".

Note that both terms, carat and point, are used by specialists. A 2 carat diamond has a diameter of 8.10 mm and a weight of 0.40 gram.

When you are looking to buy a diamond, you have certainly read some abbreviations such as ct, which is the simple way to write carat, and ct TW, total carat weight, which refers to the total number of carats in a jewel containing several small diamonds. You just have to remember these abbreviations to know the weight of a diamond.

How the weight expressed in carats affect the value of a diamond?

The weight of a diamond is expressed in carat but can also be expressed according to the diameter of the stone. Diamonds ranging from 0.05 carat to 2.00 carats have a diameter ranging from 1.00 mm to 8.10 mm and a weight of 5pts to 200 pts. The value of a diamond increases as the number of carats increases. However, a piece of jewelery with a single 1 carat diamond (the other 7 quality criteria are defined) is more expensive than if this piece is composed of a variety of several small diamonds whose 7 other quality criteria are the same as those of 1 carat diamond.

A diamond with a weight of one carat is just a problem.

The difference in price between a diamond with a weight just below the carat (for example 0.98 ct) and a diamond weight just above one carat (1.01 carat for example) is very important while the difference in weight is not visible to the naked eye.

We recommend comparing prices per carat for diamonds that also have the same 7 other quality criteria. A relationship between the weight and the diameter of a diamond can be established with a certain proportionality. The number of carats increases with the diameter of the diamond.

The higher the weight of a defined diamond (eight quality criteria), the higher the price per carat. In other words, the price per carat of a 2 carats diamond is much higher than the price per carat of 2 diamonds of 1 carat each with the same other quality criteria. The value of a given diamond (8 quality criteria) is exponential as its carat weight increases. To estimate a diamond weight, you must weigh the stone in grams, then in carats. This operation requires very strict conditions: you need a place without any air flow, no sources of heat and no vibrations. The stone must be very clean because the slightest dirt can influence its balance and falsify its real weight.

The value of a diamond is exponential with respect to the number of carats for a given combination of quality criteria. The heavier a diamond is, the higher its value per carat. This is for example the reason why a 3 carat diamond will be much more expensive than 3 diamonds of one carat with the same combination of quality criteria.

In conclusion, the weight of a diamond is the most difficult criterion to define according to whether it is still in the rough state or when it is cut.

Weight is of major importance for the estimation of its value. The heavier the diamond is, the higher its price per carat.

In addition, it should be kept in mind that a large diamond is much rarer than a small one; this is also why its value will be much higher than small diamonds with the same combination of quality criteria for the same carat weight.

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