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Boulder Opal

Pictures of Boulder Opal

Boulder Opal

Boulder Opal: The bead on the left was cut from Australian boulder opal. It weighs 1.9 carats and measures 10 x 6 millimeters. The specimen on the right is opal in andesite from Honduras. It weighs 2.9 carats and measures 8 x 13 millimeters.

What is Boulder Opal?

"Boulder opal" is a term used for a rough or a cut gemstone that displays opal within its surrounding rock matrix. Opal often forms within voids or fractures in its host rock, and specimens of boulder opal reveal this aspect of opal's origin. The contrast of color can be striking when a bright flash of opal is seen within the surrounding rock material. Many people enjoy the natural appearance of boulder opal and find these gemstones to be beautiful, interesting and educational.

boulder opal

Boulder Opal: This oval cabochon weighs 1.90 carats and measures 10 x 6 millimeters.

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