Cocktail Ring Modern 5.76 Cabochon Cut Black Opal & in Platinum & 18k Yellow GoldBlack opals are the rarest variety of opal and also the most valuable due to their dark body tone that enhances the richness of colors within them. Warm colors within black opals like yellow, orange, pink, and red are less common than cool colors. As a result, the more warm colors present, the higher the value. Strong red play of color in a black opal is the most valuable combination and that is exactly what this beauty exhibits. This stunning