What Exactly is a Diamond Carat

A diamond’s carat weight is very important and as you browse diamonds, you might notice a few other words, such as size and points, which are closely related to a diamond’s carats.

Sometimes these words can be confusing, so in this article we are going to explain exactly what a carat is and define words that are related to it, so you will be better prepared to choose a diamond.

Carat Weight vs Size – Understanding the difference

As you consider diamond carats, it is essential to understand that a diamond’s carat weight is not the same as its size. It is possible for two diamonds to have the same carat weight and yet be different sizes.

A diamond’s size is determined by its height, width and the measurements of its primary parts, including its girdle and table. The table or top of the diamond is one of the most important aspects of a diamond’s size, because it is the table that will be visible once the diamond is set in a ring.

Diamond size

What exactly is a carat?

A carat is a unit of weight used for diamonds and other precious stones. Years ago the weight of a carat varied, because each diamond capital used different seeds or grains to establish the weight of their carat. During those years, Dutch jewellers considered the carat to be equal to 0.2057 grams, while Italian gem traders defined it as 0.1972 grams. The carat’s weight was standardized in 1913 and today each carat is equal to 200 milligrams or 0.2 grams.

Diamond carat

What are points in reference to diamond weight?

In the early 1900s, gemologists calculated a diamond’s weight in carats and fractions of a carat, so it wasn’t unusual to find a gem that weighed 1+ ½ + 1/16  carats.  Gemologists eventually saw the need to be more precise in weighing gemstones and subdivided the carat into 100 “points” with each point equaling one one-hundredth of a carat. This allowed them to precisely weigh diamonds to the hundredth decimal place.

As you compare diamonds, you may find that some stones have their weight listed in carats or a fraction of a carat, while others will have their weight written in carats and points, for instance 1.12 carats.

How to determine the carat weight of a diamond?

Calculating how many carats a diamond weighs is not difficult. First, determine how many grams the diamond weighs and then divide its weight in grams by 0.2 to find its carat weight.

Here is an example: The diamond weighs 0.3 grams. Divide 0.3 grams by 0.2 and you will discover that the diamond weighs 1.50 carats.

You can also find the carat weight of a diamond by looking at its certificate. Most high-quality diamonds have a certificate issued by a reputable gem lab that lists its carat weight and specific measurements.

Tips for buying a diamond

As you shop for a diamond, don’t focus only on its carats.  The secret to finding the best diamonds is to consider their carat weight along with their size and other vital characteristics, such as colour, cut and clarity.