Estate natural Yellow & White Diamond Pendant set in Platinum,Platinum Necklace.

Yellow center natural yellow diamond surrounded by white diamonds set in 950 Platinum on an 18” adjustable platinum small box chain necklace. Weights are .53 & .364 on both center and surrounding. I don’t know which is which however. Only marked “D” on hallmark. My camera couldn’t pick up the color well. I did the best I could. Thank you for looking!