The Portugese Cut
| The Portugese Cut GemCad Derived Rendering by Bob Keller bkeller@rockhounds.com | |
|---|---|
| Angles for R.I. = 1.54 | 161 facets + 16 facets on girdle = 177 |
| 16-fold, mirror image symmetry | 96 index |
| L/W = 1.000 T/W = 0.434 T/L = 0.434 P/W = 0.585 C/W = 0.222 | H/W = (P+C)/W+0.02 = 0.827 P/H = 0.707 C/H = 0.268 |
| Vol./W^3 = 0.307 | Brightness at 0 degrees tilt for R.I. = 1.54 COS = 48.5% ISO = 52.5% |
| Pavilion | |||
|---|---|---|---|
| g | 90.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Cut to equal depth, establish size |
| p1 | 62.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet g |
| p2 | 57.00 | 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 | Meet g,p1 |
| p3 | 52.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet p1,p2 |
| p4 | 47.00 | 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 | Meet p2,p3 |
| p5 | 42.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet p3,p4 and at culet |
| Crown | |||
| c1 | 46.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet g, cut level upper girdle line |
| c2 | 41.00 | 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 | meet g,c1 |
| c3 | 36.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet c1,c2 |
| c4 | 31.00 | 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 | Meet c2,c3 |
| c5 | 26.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet c3,c4 |
| t | 0.00 | Table | Meet c4,c5 |
The Portugese Cut is a popular and time honored design for larger stones. Due to its greater than normal depth it is best matched to stones of light to rather than dark color saturation. While the Portugese Cut has a large number of facets, it can be faceted using straightforward meetpoint technique. The high degree of symmetry and relative ease with which smaller facets can be polished make this design relatively fast to cut in larger stones. The visual effect of the Portugese Cut is often described along the lines of “swirling light”.