SHAY DIAMOND TENNIS NECKLACE Eighteen and a half carats of natural round diamonds, four millimeters wide, set tight to the neck. Every stone four-prong set in 18k gold. Adjustable from 12 to 15 inches — you decide where it sits. The necklace everyone references. This is the one. Details: 18-karat gold White Diamonds: approx 18.5 cts Natural stones only Length: 12 - 15in Width: 4mm Product Number: SN196 Looking for something bespoke? Contact us . Slight variations in color, shape, and size are part of their beauty.