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Judging Sapphire Quality

Carat Weight

How Does Carat Weight Influence Stone Price?

The Titian's Eye, our 69.35 carat natural untreated blue sapphire is exceptionally rare due to its size, color, and clarity. It is the perfect gem for a serious collector.
The Titian’s Eye, our 69.35 carat natural untreated blue sapphire is exceptionally rare due to its size, color, and clarity. It is the perfect gem for a serious collector.

Large gemstones are harder to find than smaller ones.  The effect of carat weight upon sapphire value varies from color to color.  Yellow sapphires are comparatively plentiful in sizes above five carats, but five carat padparadscha sapphires are extremely hard to come by.  As with any gem, per carat prices increase with overall carat weight.  Expect steep increases in the price per carat at the one, three, five, and ten-carat levels.  Fine blue, pink, orange, or padparadscha sapphires that exceed fifteen carats are especially valuable and can fetch very high prices at auction.

Fine quality sapphire rough is extremely expensive, so quality stones are not usually cut to calibrated sizes because it could result in a significant loss of weight.  Commercial quality sapphires are more likely to conform to standard calibrated sizes.

A sapphire’s size, if expressed in a unit of weight, is called a carat (abbreviated “ct”).  A carat is a metric unit equivalent to one fifth (.20) of a gram.  One hundredth of a carat is called a point (abbreviated “pt”).  A number of small sapphires may be weighed together to give a total carat weight (abbreviated “tcw”).  Because sapphires have a high specific gravity, a one-carat sapphire will appear smaller than a one-carat diamond.

Now that you have learned the tools to determine sapphire quality, find out more about treatments and how the further effect the value of your gemstone in Common Sapphire Treatments.

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