Ultimate Guide to the 4 C’s of Diamonds: Carat

If you’ve ever been in the market for a diamond, then you have probably heard a lot about the 4 C’s of diamonds. At Noe’s Jewelry, we believe in educating our clients and the public on what these 4 C’s really mean. In this series of articles, we will discuss each of the 4 C’s to help you better understand diamond buying. The first part of this series will cover one of the most misunderstood C’s: Carat.

What Does Carat Mean?

Many people mistakenly believe that carat refers to the size of the diamond, but it actually refers to the diamond’s weight. Diamonds are always weighed in carats instead of grams or pounds. A metric carat is defined as 200 milligrams. Carats are divided into 100 “points,” which allows diamonds to be weighed to the hundredth decimal place for extreme accuracy. For example, you may see a diamond that is 0.25 carats and one that is 1.58 carats. Carat is typically abbreviated to ct.

Some weights are considered “magic sizes.” These are weights like half carat, three-quarter carat, and one carat. While a 1.00-carat diamond looks almost identical to a 0.99-carat diamond, the price difference can be significant due to the magic size of the carat diamond.

The word “carat” comes from the “carob.” Carob seeds all have the same weight, so in ancient times, they would use carob seeds to determine the weight of diamonds.

Diamonds get more expensive as the carat weight increases, because larger diamonds are rarer and more desirable, and the scaling of pricing isn’t proportionate to the scaling of the diamond size. This means that four 0.25-carat diamonds will not cost the same as one 1.00-carat diamond. When determining the cost of a diamond, the carat isn’t the only thing you need to think about. Other factors (the other 3 C’s) also help determine the value of a diamond.

Carat Weight vs. Diamond Size

The size of a diamond is heavily dependent on both the shape and weight of the diamond. Here are some common dimensions for one-carat diamonds of different shapes:

Round: 6.30 x 6.30 mm
Princess: 5.50 x 5.50 mm
Marquise: 10.00 x 5.20 mm
Pear: 8.00 x 5.50 mm

This is a good way to show that carat weight and size are not the same things, but they are very closely related.

Total Carat Weight

You’ve probably also heard the term total carat weight, which is abbreviated as ct.tw. This term tends to be a little confusing. The total carat weight refers to the total weight of all of the diamonds in a piece of jewelry. In a ring or necklace, this means the weight of every diamond on the piece. In the cases of earrings, this gets a little trickier. For earrings, the total carat weight includes the diamonds in both earrings combined. So, if the total carat weight of a pair of earrings is one carat, then each earring in the set has a half carat diamond.

When you are buying a diamond, you will likely hear the jeweler say that the center stone has a certain carat weight, but the total carat weight is higher. For example, the center stone is 1.25 carats, and the total carat weight is 2.05 carats. This means that there are 0.80 carats of additional stones on the ring.

When it comes to engagement rings, the carat weight of the center stone tends to be what people focus on. A ring that is 2ct.tw. with a center stone of less than 0.50 carat is probably not going to look as impressive as a ring that is 2ct.tw. with a center stone that is 1.50 carats. So, the total carat weight takes a backseat in this instance.

To learn more about carats, you can contact Noe’s Jewelry at 816-322-7227. If you live in the Kansas City area, stop into our Raymore store. Our jewelers would love to help you find a diamond or piece of jewelry today. Our experts have been serving the community for over 100 years, and we are one of the most trusted local jewelry stores in the Kansas City Metro Area.

Part one of the 4 C’s series: carat weight

Part two of the 4 C’s series: diamond cut

Part three of the 4 C’s series: diamond color

Part four of the 4 C’s series: diamond clarity