Old mine diamond coronet cluster ring. Set to center with a cushion shape old mine diamond in an open back rubover setting with an approximate weight of 0.55 carats, and encircled by nine round mixed old cut diamonds in an open back rubover settings with a combined weight of 0.70 carats. The total approximate diamond weight is 1.25 carats, to a scalloped coronet cluster design featuring millegrain edges, a pierced gallery and circular open backholing leading to inwardly tapering shoulders and flowing through to a solid D-shape shank. Tested platinum, early 20th Century.