An 8mm round solitaire genuine black onyx stone is set in this 14k white gold black onyx men's ring from Apples of Gold Jewelry.
The ring's band measures approx. 8.8mm at the shoulder width and 4.6mm at the bottom of the ring. The face/top measurements is 12.4mm wide.
Our men's black onyx solitaire ring is also available in 14k yellow gold, shown below.