Medieval sapphire ring. Centrally set with a single cabochon natural unenhanced sapphire in a closed back rubover setting, to an impressive drop shape bezel, the base inscribed 'MARIA + ADIVVA' translated from the Latin as 'Mary help', flanked by intricately carved shoulders featuring the forms of a matching pair of mythological beasts, the gaping mouths grasping the bezel, the wings, claws and hind legs creating the shank. Tested yellow gold, approximately 9.9g in weight, circa 14th century, accompanied by an Oxford Labs X-ray fluorescence report stating the composition of the metal and an Art Loss Register certificate.
Sapphires were a favourite choice in the Middle Ages, though so rare that they were reserved solely for royalty, upper nobility and certain high ranking clergymen. Sapphires were thought to be imbued with magical powers such as protecting the wearer from the effects of poison, preserving chastity, keeping the peace and curing snake bites.
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 | |||