Amazon.com Product Description The brilliant cherry red of this fire opal gemstone immediately draws the eye. The 5x7mm faceted oval gemstone has a weight of .51 carat and originates from Mexico. Gaze into this clear, radiant red stone, and you'll know why gemstone healers claim that it bestows positive energy, courage, and stamina upon its wearer. Just glancing at its color is invigorating. Fire opal's hardness rates between 6 and 6.5 on the Mohs scale. A somewhat sensitive gemstone, it is best suited for pendants and earrings, though it may be used in a ring if given a protective setting.