Carat Difference in Size in Cubic Zirconia

by Shanna
(U.S.)

I keep buying cubic zirconia rings, and when they arrive they look huge! I would like a 1 - 2 carat ring, but what is the carat difference so I can make better buys. Thanks!

Hi Shanna,

The carat of any type of gemstone, including man-made gemstones like cubic zirconia, is a measurement of the weight of the stone – not the size of the stone. A 1 carat stone will weigh 0.2 grams, or 200 milligrams, and the 1 carat size for each gemstone will depend on the density of the stone.

Diamonds have a density of 3.5 – 3.53 while the heavier cubic zirconia gemstones have a density of 5.5 – 5.9. Because of the difference in densities, a 1 carat cubic zirconia gemstone will be slightly smaller than a 1 carat diamond.

A 1 carat stone will look larger or smaller to the eyes too, depending on how the gemstone is cut. For example, an emerald cut stone carries most of the weight on top and an Asscher cut carries most of the weight under the top of the stone. So, a 1 carat Asscher cut gemstone will look smaller than a 1 carat emerald cut gemstone.

Cubic zirconia tends to look more like a diamond in sizes ranging from 0.3 to around 1.5 carats in size. Once you start reaching sizes of around 2 carats, a cubic zirconia looks a lot less like a diamond because of its dazzling light reflective qualities.

How can you order a cubic zirconia ring that is not too big? With a ruler!

Look closely at the description of the cubic zirconia ring, and you should see the width and length of the center stone in millimeters. If you have a 1 inch ruler or measuring tape, flip it over to the centimeter side – 10 millimeters equal 1 centimeter. Most rulers or measuring tapes will show 1 millimeter notches between the centimeter measurements.

You can mark the measurements of the cubic zirconia stone out on a piece of paper to gain a visual impression of how large the stone will look.

While using the carat sizes is a good guideline too, because of the differences in how the stones may looking depending on their cut – it is best to measure out the stone's millimeter length and width before you decide to order the ring.

I hope this info helps, and do write back if you have any additional questions!

Suzanne Gardner