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Fine Jewelry University Articles matching: “Sapphire bands”

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Fine Jewelry University

  1. Group of loose emerald gemstones

    Gem in the Spotlight: Emerald

    … and aquamarine) and are valued for their rich green color. The intensity of an emerald’s hue depends on the presence of chromium and vanadium in the crystal structure. Emerald’s Mohs hardness rating is 7.5-8 making it softer than sapphire and harder than amethyst and other quartz varieties. The refractive index of emerald ranges from 1.57 to 1.58, making it a moderately refractive gemstone. Its specific gravity ranges from 2.65 to 2.75. One of the distinctive features of …

  2. Opal Rings With Loose Opal Gemstones

    Gem in the Spotlight: Opal

    …a refractive index of 1.37 – 1.47 and a Mohs hardness of 5.5-6. This makes it one of the softest gemstones commonly used in jewelry. For reference, here are the Mohs hardness values for some other gemstones you may know: Diamond 10, Sapphire 9, Amethyst 7, and Peridot 6. Turquoise is about as hard as opal, but you would need to consider Pearl or Amber (both 2.5) to find a commonly used gem that is softer than opal. Common Opal Treatments There are several different …