Skip to product information
A polished Cold Mountain Thunderegg specimen featuring grey to deep mauve purple brecciated jasper with brown detailing and an area of translucent chalcedony.
Polished face: 11.5cm x 6.7cm
Approx. 1.75" deep
12.6oz
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.