All carat weights and measurements are approximate and may vary slightly from the listed dimensions. *T.W. (total weight) is approximate. 1/3 carat T.W. may be .28 to .36 carat. **1/5 carat T.W. may be .17 to .23 carat. ***1/2 carat T.W. may be .45 to .57 carat. Treatment code N. See Gemstone Treatments for further information.