| 摘要 |
<p>Gemstones are cut such that the pavillion facets are curved facets (12, 14, 16) and are arranged in pairs around the pavillion and so disposed relative to each other and the crown and table of the gemstone that light entering the stone through the crown and meeting the first curved facet of a pair is converged and reflected on to a second curved facet of that pair from which it is reflected to the crown, faceting machine for producing such facets is disclosed.</p> |
