SOLD Vintage Three Stone Diamond Engagement Ring Klepner's Fine A vintage three stone diamond ring 1. Antique 3 Stone Diamond Ring, 1.76ct in 18ct Gold Rings Jewellery Three Stone Diamond Victorian Style Ring For Sale at 1stDibs Antique Victorian 3 Stone Diamond Ring Old Mine Vintage 14 Karat Gold Vintage Three Stone Diamond Ring, Vintage Engagement Ring, Two Tone. A vintage trilogy ring. Set with three old brilliant cut white diamonds, centre 3mm and each side a 2. 4mm diamond. Total estimated at 0. 20 carats, colour H j, clarity Si All diamonds set in to a platinum head , 11x4mm , square design, early 20th century. Weight 2. 2grams. Stamped 18CT PT, tests as 18 carat gold, platinum shoulders, no hallmarks required for this period Size K, we can resize free of charge.