When it comes to gemstones, carat is one of the most significant factors to assess the value. It is the most important one out of four Cs that are used to describe a gemstone.

Carat is the standard unit of measure for gemstones and pearls. One carat unit equals to 200 milligrams or 1/5 of a gram. The abbreviation for carats is CT or ct. More often, the carat weight is described in decimal fractions. Every gemstone has a unique density, therefor 1 carat of one stone may differ in size and volume than 1 carat of another gemstone.


Origin of the Term:

The term carat stems from the ancient unit of measure for diamond weight, the carob seed. This seed is even in weight, and that is why gem trader used them for weighing references. But due to the varying size of the seed, there was much uncertainty and vagueness in gemstone weight.

With the advent of technology and digital equipment, a lot has changed. There is a precise and accurate measurement technique that offers uniformity around the globe.

How is Carat Weight Measured?

Accurate measurement holds supreme importance when it comes to weighing gemstones. Any change or difference in the weight can broadly impact the value of a gem. To achieve absolute precision, specialized instruments are used by traders and jewelers. Carat weight is generally measured to the thousandth of a carat and then rounded to the nearest one hundredth.

Does Carat Weight Affect the Size of the Gemstone?

Carat weight plays an important role in determining the value of a gemstone. However, as every gemstone has a unique density, the 1 carat of one stone may differ in size and volume than 1 carat of another gemstone.

How to Determine the Carat Weight of a Gemstone?

To calculate the gemstone's carat weight, identify the weight in grams of the gem and then divide it by 0.2 to find its carat weight.