18-karat rose gold, tourmaline and diamond earrings Kimberly McDonald, Kimberly McDonald uses natural gems in her stunning, handmade designs. Centered with 27.19-carats of watermelon tourmaline slices, these 18-karat rose gold earrings are a beautiful way to inject color into your jewelry collection. The 18-karat blackened white gold setting beautifully highlights the 1.88-carats of diamonds Gender: Female. Age Group: Adult.