The 18 carat gold band is quite fine, and the three diamonds are set into platinum. The hallmarks for the date are no longer visible but I'd say from the style this is from the 1940's or earlier. The setting is 7 mm across at the widest part, and the central diamond is 4mm in diameter, while the two on either side are 3mm in diameter approximately half a carat of diamonds.
The ring weighs 2.2 grams. The ring is Size M 1/2 although it could easily be re-sized if required and we can have this done for UK customers if needed. We are a family run jewellers in Ireland with over 75 years of experience in jewellery, antiques and much more and we welcome you to our online shop which has a growing collection of antiques and new jewellery in both silver and gold.
The item "VINTAGE 18CT GOLD & PLATINUM DIAMOND TRILOGY RING SIZE M 1/2, ENGAGEMENT, TWIST" is in sale since Friday, November 18, 2016. This item is in the category "Jewellery & Watches\Fine Jewellery\Fine Rings\Diamond". The seller is "rogersilverstore" and is located in Carrickfergus, Antrim. This item can be shipped to United Kingdom.