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A polished Cold Mountain Thunderegg specimen pair featuring brecciated jasper in deep, muted plum with brown, grey-blue, and tan hints with a bolt of chalcedony filling one of the fractures.
Polished faces: 8cm x 6.6cm and 8cm x 6.5cm
Approx. 1.75" deep
1lb 2.1oz 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.