| 摘要 |
<p>The present invention provides an apparatus and method for assessing optical performance quality of a gemstone. The apparatus comprises a means for holding at least one gemstone (50), a dome (10) adapted over the means for holding surrounding/covering the gemstone; at least one light source (20a, 20b) adapted inside the dome to throw light at the centre of the dome. The method for assessing optical performance quality of a gemstone, comprises steps of providing a gemstone to be assessed for optical performance quality, holding the gemstone under a dome; focussing light over the gemstone, and assessing optical performance quality of the gemstone through unaided eyes by viewing Effective Total Angular Size (ETAS) pattern of the gemstone reflected over the dome.</p> |
