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Diamond Carat Weight

What is a Diamond Carat?

The term carat is often misunderstood. It refers to a diamond's weight, not its size. When comparing diamonds with different carat weights, consider the cut as well. A high carat weight diamond with a poor cut may look smaller than a diamond with a smaller carat weight and a very good cut.

Diamond Carat Price

Carat has the biggest impact on price largely because of social tropes, marketing, and pop culture. And although carat does play a factor in the cost of a stone, a diamond’s cut is arguably most important when it comes to price. That’s why it’s a smart idea to read our experts’ tips to help you choose the best diamond carat weight for you.

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The Brief History of Diamond Carat

The term carat comes from the ancient method of weighing precious metal and stones against the seeds of the carob tree—which were considered to be even in weight. It wasn’t until 1907, at the Fourth General Conference on Weights and Measures, when it was agreed upon that one diamond carat would be equal to 200 mg, or .2 grams, of a diamond. Carats can also be measured in points; 100 points equals a full carat.

4 Things to Know About Carat

  1. “Buy shy” to save money. Select a carat weight slightly below the whole and half-carat marks. For example, instead of a 2.00 carat diamond, consider buying a 1.90 carat weight. This will save a considerable amount of money, and the slight difference will never be noticed.
  2. Splurge on cut This is the most important factor because it maximizes sparkle. A high-quality, high-carat diamond with a low-quality cut can appear dull and lifeless.
  3. Fancy shapes cost less per carat. The most important thing to realise about fancy-shaped diamonds is that they are generally less expensive than an equivalent round diamond. Additionally, fancy shapes can appear larger than their actual diamond carat weight size, especially when placed in a halo setting.
  4. Keep ring size in mind. The smaller the finger, the larger the diamond will appear. A 1.50 carat diamond solitaire looks much larger on a size 4 finger than a size 8.

Carat Has the Biggest Effect on Price

You can thank movies, mass media, and advertising for the emphasis that people put on carat in relation to diamond quality. Carat weight has become an indication of a person’s status and wealth, but when it comes to diamonds, bigger is definitely not always better. Instead, focus on a balance of the 4Cs: cut, clarity, colour, and carat to make a smart purchase.

Diamond Carat Size Chart

This chart illustrates differences in diamond size based on carat weight and how diamonds of different carat weights and shapes will appear when viewed from the top down. Your diamond measurements may differ from the chart in length/width ratio, table, and depth.

Download Chart

A Few Additional Carat Tips Before You Buy a Diamond

  1. Certain settings can make a diamond appear larger. A very popular setting to achieve this effect is the halo. This setting has a ring of small diamonds around the centre stone. The ratio of the small to large diamonds skews the perspective in your favour, making the centre diamond seem larger.
  2. Band size affects the look of a diamond’s carat. Selecting a thin band creates a perspective that makes the centre stone appear larger. A popular band to achieve this is the pavé, which features small diamonds embedded in the band.
  3. Understand total carat weight (CTW). Total carat weight is the measurement of all the diamonds in any given piece combined. So, be sure to inquire about the weights of the individual diamonds in any piece that you are buying.
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Manoj Tiwari is Blue Nile's Director of Diamond Supply Management
Manoj Tiwari
Director of Diamond Supply Management
Manoj Tiwari's more than 30 years of experience spans every aspect of the industry...

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