A showpiece for him, this richly hued ring is a perfect match for his casual-to-business personality. A singularly striking 8. 0mm square black onyx rests at the center of this style, flanked by sparkling diamonds in ideal symmetry. Radiant with 1/5 ct. T. W. Of diamonds and a bright polished shine, this 10k gold style is a great go-to look he's sure to appreciate.