Black Spinel Cocktail Ring in Recycled Sterling Silver, White Gold, Yellow Gold or Rose Gold.12mm round natural black spinel ringSimilar in appearance to black diamond and black onyx, but stronger than onyx- Spinel is polished to a shine and beautifully faceted.Spinel is phenomenally durable, a 9 on the MOHS hardness scale, and this stone is a whopping 12mm across, just around 1/2 an inch.The solitaire sits about 8mm off the finger and pairs nicely with a band ring, or as a solitaire statement r Luxury Black Spinel Diamond Ring, Hardness Scale, Black Spinel Ring, Treasure Jewelry, Spinel Ring, Black Spinel, Recycled Sterling Silver, Cocktail Ring, Black Rings