The center cabochon blue sapphire fits perfectly bezel set in the handmade platinum ring from the 1920's. The sapphire weighs about 4.5ct and has rose cut side diamonds weighing about .30tcw. In yellow gold, on one side is a globe on a stand, and the other side has a book with feather pen.
Platinum Art Deco .75ct Cushion Sapphire & .80tcw diamond Ring, c1920, 4.0g, size 7.75
Platinum Art Deco Ring Set 2.57ct Round Blue Sapphire & 1.80tw OEC Diamonds, s6.5
Platinum 2tcw Sapphire & .96ct and .72ct Diamond Bypass Art Deco Ring, c1930's, s8
Platinum Art Deco 2.91ct Round Sapphire & 2 OEC Diamond 1.46ct & 1.48ct 3stone Ring s7.5