This ring features your choice of an 8mm or 6mm tungsten carbide band that is inlaid with glowstone & black fire opal that flickers brilliant deep reds, blues, & oranges. The bands of the rings are beveled on the inside for a comfortable & smooth fit & are cobalt-free for those with metal allergies. Tungsten carbide is extremely strong & scratch-resistant making it a perfect material that will last a lifetime. All together the black fire opal, Black glowstone inlay, & black ceramic create an interesting yet simplistic & sleek ring. Please note: Because the glowstone in this ring is pigmented black, the glow is much more subtle than it would be when un-pigmented. If this is a deal-breaker for you, feel free to contact me for other options. Tungsten Carbide & Fire Opal Blackout Glow Ring. Black Ceramic Opal Men’s Women’s Sizes 5-13