Large Amethyst Paste Ring Antique Georgian foiled back brass crimped setting 12k solid rosy gold band bague glass purple US 6.5 M

Large georgian amethyst paste glass ring with a bombed back and foiled stone. The setting is in brass and the band is 12k solid rosy gold. The stone is glass and purple The ring size is a US 6.5, UK M and 53/54 The paste with bezel measures: 22 x 16 x 9 mm and is wonderfully set in a closed back bezel, is it foiled back and it’s set in the traditional Georgian setting known as cut-down or crimped setting. I would date it as early 1800s to 1820’s. The band was added later and it tests at at least 12k and is rosy gold. It is 1.8 mm width x 1.1 mm thickness The band is 6mm wide and 1mm thick. The weight is 6.1 grams. Thanks for reading!