The Short on Diamond Carat Size



At Cut Fine Jewelers, engagement rings are our specialty. Rather than just try to sell you an engagement ring, it is our goal to serve as a guide on precious metals, gemstones, settings, and other factors of fine jewelry, so you are able to realize an engagement ring that is truly and uniquely you.

If you have begun exploring options for a loose diamond or an engagement ring, there is a good chance you have come across the term "diamond carat." 

Diamond sizes and how diamonds are measured is the most commonly discussed aspect of any diamond. Diamond carat size is on many wish lists, and it's in every headline when a celebrity gets engaged. But have you ever wondered what carat size really means?

Read on to understand the carat weighing system used for diamonds and why the weight of every diamond is unique.


The Short on Diamond Carat Size

Carats (ct) are a unit of mass used to weigh diamonds, gemstones, and pearls. The carat is a very old standard of measurement that extends back to at least the 16th century for measuring diamonds. The carat probably has its origins in the carob seed used in Greek and Roman times as a standard form of small measurement. Even though we think of carat as a measuring the size of the diamond this is not the case. The carat is a weight measurement so the appearance of two stones that are both 1 carat diamonds can be somewhat different.

In today's market, a carat is equal to 200 mg. This standard of measurement was adopted early in the 20th Century by the General Conference of Weight and Measures. The CGPM, established in 1875, is the same organization that established the metric system and encouraged its adoption throughout the world for the standardization of all weights and measurements.

Each carat is divisible by 100 points, each weighing 2 milligrams. Prior to the standardization and adoption of the carat system different countries used slightly different standards of measurement for diamonds and gemstones making it very difficult to compare one stone to another without placing them side by side. The adoption of the carat meant that a diamond seller in Africa and a diamond buyer in Brussels could reach an agreement concerning a particular stone much more easily.

Limitations of the Carat System

The carat system has its limitations because diamonds are shaped and cut differently. A 1 carat diamond can be cut long and deep and it will look visibly smaller than a diamond that is cut shallower. The different cuts of the stones, for example cushion, round, marquise, square, emerald or pear will also weigh different amounts because the cuts are different. In other words, how the stone is cut and its shape can have a dramatic impact on the presentation of the stone.

Carats and Pricing

The size of a diamond dramatically influences its price. (This is where the carat becomes a very valuable tool!)

Larger diamonds are rare compared to smaller diamonds so the price per carat substantially increases based on the weight of the stone. To put it into perspective, a 5 ct diamond may cost $45,000 per carat while a smaller stone less than 1/2 ct may cost $2,400 per carat for a diamond that is the same in all other categories.

To learn more about diamonds and to see how stones in different sizes look, please visit our showroom or book an appointment here.


Anything Is Possible at Cut Fine Jewelers

Custom engagement rings are our specialty. We will work with you to find the perfect gemstone in the perfect carat size as we build your dream ring from scratch. Learn about our custom jewelry design process here





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