| 摘要 |
PROBLEM TO BE SOLVED: To provide an oval cut diamond, when looking a pavilion from the bottom, showing characteristic patterns, namely at least, four heart-shaped reflected light patterns in lower girdle facets. SOLUTION: A cut is provided with a columnar girdle, a crown having an octagonal table facet in its top part, and a pavilion. The cross sectional outline of the girdle has an elliptic shape or a shape similar to an ellipse, the ratio of short diameter to long diameter of the cross section (b/a) is 0.6 or more, preferably more than 0.7. The long radius Del of the table facet has a value of 0.375a or more expressed by the long diameter (a). The pavilion has eight pavilion main facets and the sixteen lower girdle facets. The pavilion angle (p) has a same value between 38.0°-45.0°. A distance Gd from the central axis to the lower girdle facets has a value between 0.15a-0.4a expressed by the long diameter (a). COPYRIGHT: (C)2005,JPO&NCIPI
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