This is a wonderful "one of" Mabe Pearl and Montana Sapphire ring. It is from the 1920's or 1930's and the Sapphires are a robins egg blue and absolutely untreated. The Sapphires very from 0.05 - 0.15 CT each.
The Mabe Pearl is 23 mm in diameter (1"=25 mm). It is size 7 and weighs 10.2 grams. This gram weight further attests to the true Platinum shank.
This is an eye catching and unique ring and the blue Sapphires will not go unnoticed. Minor abrasions to Pearl otherwise perfect, from a local Litchfield, CT estate.