What is a carat?


What is a carat?

The carat used in jewelry comes from the name of a tree: the carob tree. This tree grows mainly in the Mediterranean region. It produces fruits whose seeds have the particularity of always having the same weight. Since ancient times, seeds have been used as a unit of measurement in all civilizations.

In jewelry, the carat refers to two measures that are difficult to distinguish. The first is probably the best-known, being the unit of mass of precious stones such as diamonds. The second is the purity of precious metals such as gold. The carat is also the criterion that influences the price and value of these metals and precious stones.

What are the differences between gold and diamond carats?

Gold carats

The carat of gold is the unit of measurement used to indicate the purity or fineness of gold, i.e. the quantity of pure gold (also called fine gold) present in your jewelry. It is represented by the symbol "ct" or "k". The greater the quantity of pure gold, the better the trade-in rate for you. The purest form of gold is 24k.

As one of the softest materials, gold has to be combined with alloys to harden and make jewelry. Gold with a lower carat value, such as 18k or 14k, means that it is mixed with other metals to create a harder, more durable material. Alloys used to harden gold include zinc, copper and nickel.

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24-carat gold is the purest form of gold, and therefore contains the fewest alloys. 14-carat gold is an alloy of 58.5% gold and 41.5% other metals.

  • 24-carat jewelry: 99.9% fine gold.
  • 18-carat jewelry: 75% fine gold.
  • 14-carat jewelry: 58.5% fine gold.
  • 9-carat jewelry: 37.5% fine gold.

The color of gold can also vary according to the metals with which it is mixed. For example, rose gold is created by mixing gold with copper, while white gold is created by mixing gold with silver or palladium.

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Corsica Giulia Collection

Diamond carats

Among gemstones, we find the diamond. A diamond's unit of weight is expressed in carats, and is valued according to its cut, color, clarity and weight. 

The cut of a diamond is one of the most important things, as it is the cut that reveals its brilliance. Diamond color is also an important characteristic, graded on a scale from D to Z, with D being the best quality with a very pure white. In addition, diamonds contain inclusions (i.e. impurities), so they are graded according to the visibility and number of these impurities. The best-known criterion is the diamond's weight. This is a measurement based on a metric system widely used in the jewelry world. For example, 1 carat of diamond is equivalent to 0.20 grams. The higher the diamond's grammage, the higher its carat and the higher its value:

  • 8-carat diamond: 1.60 g
  • 5-carat diamond: 1 g
  • 3-carat diamond: 0.60 g
  • 1-carat diamond: 0.20 g

The prices of large stones are not proportional but exponential: a 1.5-carat diamond is 3 times the weight of a 0.5-carat diamond, but the price of the 1.5-carat diamond can be between 5 and 7 times higher than the other diamond.

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Delia Collection

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Differentiating between the two types of carat

Gold and diamonds make a great combination for jewelry. Gold and diamond accessories are jewelry that represents a safe and eternal purchase. There are several essential differences between the carat used to measure the purity of gold and the carat used to measure the weight of diamonds. The most important difference is the unit of measurement. The carat used for gold is a proportion, 24k gold being the purest form of gold. The carat used for diamonds, on the other hand, is determined by a combination of factors, including cut, color, clarity and carat weight.

To find out more about diamonds, read our article :

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