Last updated on December 27, 2022
The terms “diamond size” and “carat weight” are often used interchangeably; however, these two terms actually refer to different characteristics. Let’s see the difference between diamond size vs carat weight and learn why you need to pay attention to both factors when buying a diamond.
What Is Diamond Carat Weight?
Carat weight (ct) is the unit of measurement for the physical weight of diamonds. It originates from the ancient method of weighing precious metals and gemstones against the seed of the carob tree. At the time, carob seeds were considered to be even in weight and were used as weighting references by traders. As you could guess, carob seeds varied in size, and the actual weight of the gems could vary by around one metric carat.
It wasn’t until 1907, at the Fourth General Conference on Weights and Measures, that it was agreed upon that one carat would be equal to 200 milligrams or 0.2 grams. Nowadays, carat weight is measured using highly accurate and calibrated digital scales capable of measuring even extremely small weights.
In terms of gemstone weight, there is also the term “point”. A point is one-hundredth of a carat, and 100 points are equal to 1 carat. Points are used to describe the weight of diamonds that weigh below one carat. For example, a diamond that weighs 0.25 carats may be referred to as a twenty-five-pointer stone.
Carat weight is one of the four main components (4Cs) of a diamond, along with colour, clarity and cut, that indicate the quality of the stone and determine its value. Diamond price increases with carat weight because larger diamonds are rarer and more desirable as a result. However, two diamonds of the same carat weight can vary in price depending on the other three factors of the diamond and other pricing criteria.
What Is Diamond Size?
The term “diamond size” refers to the dimensions of a particular stone. They include a diamond’s table size, total depth, pavilion depth, crown height, girdle diameter and culet size. Each of these measurements, together with some other factors such as angles, determine a stone’s proportions (cut quality) and allow us to understand how large a diamond is.
As you can see, diamond size and carat weight refer to different characteristics, meaning two diamonds of the same carat weight and shape may differ in size depending on their dimensions. And vice versa, two diamonds of the same dimensions may differ in carat weights.
It is worth mentioning that buyers are usually interested in the width and height of the diamond. However, you should not forget about the overall proportions of a stone as well. Meaning if there is even a slight misalignment in proportions and angles, the stone will not reflect the light properly and not exhibit the maximum amount of sparkle and brilliance.
Diamond Size vs Carat Weight
Carat weight is one of the most important price determinants. The bigger the diamond, the higher its price per carat. This is the reason why cutters try to minimize the waste of the rough and maximize the carat weight of the finished stone. However, this does not mean that cutters have unlimited leeway when deciding on a stone’s size since carat weight puts a certain limit on a diamond’s dimensions to reach the best proportions.
Proper dimensions determine the stone’s cut quality which is also one of the major pricing factors. That is why cutters try to balance carat weight and proportions to find the right size that will provide the best price for the stone.
Unfortunately, many buyers focus on the largest diamond for the price they are ready to pay. However, this is never a good idea in terms of diamonds, as diamonds are all about quality. Of course, you can ignore cut quality characteristics and buy a shallow diamond to show off, but the truth is that you get a low-quality stone that looks large face-up.
Always remember that the more proportional the stone, the better cut quality it has and the more sparkle and brilliance it shows. The stones that have poor cut do not properly reflect light and look dull as a result. So, when looking for a diamond, always check its cut grade, as the best stones balance carat weight and proportions.
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