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CMT156pr Cold Mountain Thunderegg Specimen Pair


A polished specimen pair featuring sandy yellow, dusty pink, and dark purplish brown, with two sections of translucent and blue-gray chalcedony with faint banding.

Left: 2.5" x 4.25" x 1.5"
Right: 2.5" x 4.5" x 1.75"
1 lb 3 oz together

Cold Mountain Thundereggs are from the Sierra Mountains in Mexico. The thundereggs can contain water banding and feature red, mauve, or black “webbing.” While technically a rhyolite due to its thunderegg nature, Cold Mountain Thundereggs are highly silicate and feature large amounts of brecciation that has also been filled with silica, so this material takes an exceptional polish, making it ideal for both cabochons and specimens.