Polished Thunder eggs
$30.00
Sale price
$30.00
Regular price
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Polished thundereggs, which are spherical, nodule-like rocks formed within rhyolitic volcanic ash layers.
What is a Thunderegg?
On the outside, thundereggs often look like ordinary, rough rocks. However, when cut and polished, they reveal a core of chalcedony that can be followed by depositions of agate, jasper, or opal. These internal structures often display beautiful arrays of colors and swirling geometric patterns. Thunder Eggs are UV reactive.
Key Characteristics
Formation: They form when mineral-rich hydrothermal fluids fill voids in lava flows and solidify over time.
Size: Most are baseball to softball-sized, though they can range from a few centimeters to several feet in diameter.
Locations: Many high-quality specimens come from regions like Oregon (e.g., the Ochoco Mountains or Priday Beds) and New Mexico.
Folklore: The name "thunderegg" is believed to originate from Native American folklore, associating them with the sounds of thunderstorms.
Polishing and Care
Polishing thundereggs is a multi-step lapidary process. Rough eggs are often cut in half using a saw to reveal the internal core. The cut face is then ground and polished to a mirror-like finish using increasingly fine grits. Smaller fragments or whole nodules can also be tumble-polished in a rock tumbler.
Polished Thunder eggs
$30.00
Sale price
$30.00
Regular price