You may have seen the designation CTW on diamond jewelry and wondered about its meaning. We will help you understand the meaning and how the term is applied. The term stands for Carat Total Weight. Here’s how it’s used:
What Does Carat Total Weight Mean?
First of all, a carat is a unit of weight for gemstones, so this measurement will tell us how much all the stones in a piece of jewelry weigh. Let’s say you have a diamond ring with a larger stone in the center of about 1 carat. Other stones surround it in a circle. Let’s say there are 8 of them and they are each 1/8 carat in weight. There are 2 stones on either side of the center (4 altogether) and they each are 1/8 carat. So, you have 1 carat plus 8 x 1/8, or another 1 carat, and then 4 x 1/8 or ½ carat on the side for a total CTW of 2 ½ carats. See how that works?
Incidentally, a carat weighs exactly .2 grams, so in the above example, .2 x 2.5 gives us .5 grams.
You may see variations for this designation. The stamp could read TW, or total weight. Another could be stamped DTW, or diamond total weight. They all mean exactly the same thing.
And not to confuse you, but you need to know that a carat is not the same as a karat. They are pronounced the same, but they mean totally different things. As we’ve already told you, a carat is a measure of weight. A karat, on the other hand is a measure of purity. Commonly applied to gold, the karat value tells you how much gold is in your jewelry. For example, if your gold jewelry is stamped 14K (14-karat), this means it has 14 parts of gold in it out of a possible 24. The other 10 parts are some other metal. Pure gold is 14-karat.
Why Do You Need to Know about CTW?
Quite simply, the more CTW the better if you are buying diamonds. You can take the CTW and divide the price by that number to determine the price per carat. Just keep in mind that not all diamonds are equal. Bigger diamonds are worth more because they are more rare. Not all diamonds are of the same clarity and beauty.
The CTW is just one of the factors you can use to judge the value of a diamond you are evaluating, but it is surely a useful one, and may even serve as a bargaining chip if you are negotiating the price of a piece of jewelry.