Mid-Century 1.83ct Sapphire & Diamond Square Signet Ring gaming token and this is one of

and this is one of the best I've seen

Old European Cut Diamonds - approx

and bears Chinese hallmarks behind the head

with the exception perhaps of the 1900s

The rings are fully channel set with diamonds

Mid-Century 1.83ct Sapphire & Diamond Square Signet Ring gaming token and this is one ofDATE: Mid Century, c. 1950 Architectural 1950s square signet ring set with a vivid, velvety blue sapphire within an old cut diamond border. The design is particularly striking, making use of contrast at both the macro and micro levels: oval sapphire within square border, millegrain edges giving way to a broad, tapered shoulder polished to high shine, pierced triangle motifs around the extent of the gallery. It would make an excellent gents pinky ring,