A rare amethyst and enamel double mourning ring, circa 1756, centring on a cushion-shaped amethyst

A rare amethyst and enamel double mourning ring, circa 1756, centring on a cushion-shaped amethyst in a closed-back setting, between fleur de lis shoulders, to a band designed as entwined ribbon scrolls applied with black and white enamel, the dedicatory inscriptions 'JNO POWELL OB 6 OCT 1756 AE 35' and 'ELIANOR POWELL OB 27 SEP 1756 AE 66' in reserve, size J1/2