4.66 ct. Australian Boulder Opal

  • This large boulder opal sparkles with greens and blues. A loose stone can be great for collectors, or to make a beautiful piece of jewelry!

    1. 4.66ct Boulder opal
    2. Mined in Queensland, Australia
    3. 8.3mm x 18.6mm x 3.4mm 


    Opal is an October birthstone and the 14 year wedding anniversary stone.

      MINERAL: Hydrated Silica
      CHEMISTRY: SiO2•nH2O
      COLOR: All colors
      REFRACTIVE INDEX: 1.37-1.47
      SPECIFIC GRAVITY: 2.15 (+0.08, -0.90)
      MOHS HARDNESS: 5 to 6.5
  • If you need additional information regarding any of our gems or stones please contact us at: shop@rockshopjewelry.com