The vintage cocktail ring does not have a metal mark but was tested with platinum acid and  A AuRacle tester to be solid platinum and weighs 9.8 grams. The top is in a umbrella shape. Set in the center is a nice round blue natural tanzanite with an approx weight of 1.75 cts. It is surrounded by 11 round brilliant natural diamonds . The rounds are surrounded by 2 marquise and 14 straight baguettes. The total diamond weight is approx 3.75 cts.  The diamonds range from VS 2 TO  SI1.  The ring wears to a size 7.75 and can be resized by your local jeweler.