Obs. A finger-ring made of two separable halves: = GEMEL 4, GIMMAL 1. Cf. the description in Dryden, Don Sebastian, V. i:
  ‘Yhose rings … a Curious Artist wrought ’em: With joynts so close, as not to be perceiv’d; Yet are they both each others Counterpart. Her part had Juan inscrib’d, and his had Zayda.… and in the midst, A heart divided in two halves was plac’d.’

1

1604.  Shaks., Oth., IV. iii. 73. Marry I would not doo such a thing for a ioynt Ring,… nor any petty exhibition.

2

1703.  Lond. Gaz., No. 3897/4. Lost or stolen,… a Box,… in which were … 3 Rose Stone Rings, 24 Joint Rings.

3