If you leave your details, we can arrange a viewing with you to tell you more about this item.
Colour change Ceylon sapphire and diamond coronet cluster ring. Centrally set with a cushion shape old cut natural unenhanced blue/purple colour change Ceylon sapphire, blue in daylight, purple in incandescent light, in an open back rubover setting with an approximate weight of 8.50 carats, surrounded by eighteen round old cut diamonds in open back grain and rubover settings with a combined approximate weight of 0.80 carats, to an elegant coronet cluster design featuring polished scalloped edges, an intricately pierced gallery and open backholing, the tri-split shoulders with ridged detail flowing to a solid shank. Tested platinum, circa 1910, accompanied by Gemmological Certification Services report #79197-90.
Inside diameter (mm) |
USA | UK | China India |
European |
---|---|---|---|---|
11.63 | 0 | |||
11.84 | ¼ | |||
12.04 | ½ | A | ||
12.24 | ¾ | A½ | ||
12.45 | 1 | B | 1 | |
12.65 | 1¼ | B½ | ||
12.85 | 1½ | C | ||
13.06 | 1¾ | C½ | 41 | |
13.26 | 2 | D | 2 | 42 |
13.46 | 2¼ | D½ | ||
13.67 | 2½ | E | 3 | 43 |
13.87 | 2¾ | E½ | ||
14.07 | 3 | F | 4 | 44 |
14.27 | 3¼ | F½ | 5 | 45 |
14.48 | 3½ | G | ||
14.68 | 3¾ | G½ | 6 | 46 |
H | 47 | |||
14.88 | 4 | H½ | 7 | |
15.09 | 4¼ | I | 48 | |
15.29 | 4½ | I½ | 8 | |
15.49 | 4¾ | J | 49 | |
15.7 | 5 | J½ | 9 | 50 |
15.9 | 5¼ | K | 51 | |
16.1 | 5½ | K½ | 10 | |
16.31 | 5¾ | L | 52 | |
16.51 | 6 | L½ | 11 | |
16.71 | 6¼ | M | 12 | 53 |
16.92 | 6½ | M½ | 13 | |
17.12 | 6¾ | N | 54 | |
17.32 | 7 | O | 14 | 55 |
17.53 | 7¼ | O½ | 56 | |
17.73 | 7½ | P | 15 | |
17.93 | 7¾ | P½ | 57 | |
18.14 | 8 | Q | 16 | |
18.34 | 8¼ | Q½ | 58 | |
18.54 | 8½ | R | 17 | 59 |
18.75 | 8¾ | R½ | ||
18.95 | 9 | S | 18 | 60 |
19.15 | 9¼ | |||
19.35 | 9½ | S½ | 19 | 61 |
19.56 | 9¾ | T | ||
19.76 | 10 | T½ | 20 | 62 |
19.96 | 10¼ | U | 21 | |
20.17 | 10½ | U½ | 22 | 63 |
20.37 | 10¾ | V | 64 | |
20.57 | 11 | V½ | 23 | |
20.78 | 11¼ | W | 65 | |
20.98 | 11½ | W½ | 24 | |
21.18 | 11¾ | X | 66 | |
21.39 | 12 | Y | 25 | 67 |
21.59 | 12¼ | Y½ | 68 | |
21.79 | 12½ | Z | 26 | |
22 | 12¾ | Z½ | 69 | |
22.2 | 13 | 27 | ||
22.4 | 13¼ | |||
22.61 | 13½ | |||
22.81 | 13¾ | |||
23.01 | 14 | |||
23.22 | 14¼ | |||
23.42 | 14½ | |||
23.62 | 14¾ | |||
23.83 | 15 | |||
24.03 | 15¼ | |||
24.23 | 15½ | |||
24.43 | 15¾ | |||
24.64 | 16 | |||