Diamond University – Carat Weight

What is Diamond Carat Weight?

Carat weight refers to the physical size of the diamond. This is the only property of a diamond that is irrefutable and quantifiable. 1 Carat = 200 milligrams (measured with a carat scale). This is also the first feature that comes to mind first, for most, when thinking of diamond’s worth. However, similar to a person’s weight, not all diamonds of the same carat will appear the same size. A 2ct diamond with a shallow cut will appear much larger (from the top down) than a 2ct diamond with a deep cut.

What is Critical Weight?

Carats are broken down into 100 points, with bench markers at every .5 carat (.5ct, 1, 1.5, 2, 2.5, etc) – these tiers determine the diamond’s critical weight. The price of a diamond jumps drastically at every .5ct, thus the difference between a 1.48ct and 1.5ct will be undetectable to the naked eye, yet has a significant effect on pricing.

Simple Ways to Estimate Carat Weight

In order to determine a diamond’s exact carat weight, a professional jeweler’s scale must be used. However, getting a rough estimate of a diamond’s weight can be achieved using these two common household items: a pencil eraser and a ruler. Simply place your diamond next to either of these objects and take a clear photo. From this picture we can help give you a rough carat weight approximation.

Round in shape, and not in a mounting (loose) – Place your diamond face down (the top resting flat) directly on top of a ruler, using the mm/cm side.

Round in shape, and set in a mounting – Hold the diamond facing up. Place the pencil eraser so the top is even with the top of the diamond.

Fancy shaped (non-circular), and not in a mounting –Place your diamond face(top) down.Closely align a ruler next to the diamond, lengthwise, so that it can be easily measured (in mm/cm).

Fancy shaped, and set in a mounting – Hold your diamond so that it is lengthwise and face up. Place a ruler next to it so that it can be measured lengthwise (in mm/cm).