This vintage 1970's 0.30tcw Natural Diamond Marquise Cut Solitaire Engagement Dinner Ring is 18k Yellow Gold. The diamond is H/I color and I2 clarity. The total ring weight is approximately 3.67g stamped "18k". The ring is size 6.5 and the polish/symmetry is good. The ring is authenticated by AGA appraisal certificate no. 11993. This unique ring is a beautiful and timeless treasure.