Carat Size Question

[heather318]

Hi. I have a question about dimensions and carat size.

My ring has a princess cut center stone that the appraiser measured at 4.47 x 4.28 x 2.59 and she classified it as .44

Can somebody explain the mm dimensions to me? It seems like the dimensions vary SO much. How does this ultimately correlate with carat size? How is carat size determined for princess cut diamonds?

 

[Hest88]

Carat isn''t a measurement of size; it''s a measurement of weight. Although a diamond pro can give a pretty good estimate of carat by the dimensions--and a really experienced one would probably get awfully close to the right carat weight even just through eyeballing--if you want to be certain of the exact carat you''d need the diamond loose, and weighed on a properly calibrated scale.

 

[stebbo]

Date: 7/26/2007 12:43:54 AM
Author:heather318
Hi. I have a question about dimensions and carat size.


My ring has a princess cut center stone that the appraiser measured at 4.47 x 4.28 x 2.59 and she classified it as .44


Can somebody explain the mm dimensions to me? It seems like the dimensions vary SO much. How does this ultimately correlate with carat size? How is carat size determined for princess cut diamonds?

4.47 x 4.28 = width x length
2.59 = depth

The carat size is its weight, where 1 carat = 200mg - so your stone would weigh 88mg.

3d scans of the diamond and complex geometrical computation are required to accurately calculate the weight. Even then, scanning inaccuracies and non-uniform densities can give discrepancies to the measured weight.

Your appraiser either removed the stone and weighed it or approximated it using the dimensions above and tables and/or experience, whilst assuming symmetry and other proportions.

0.44 carat is in the right ballpark however for those dimensions in case you don't trust them!