Thunder Egg

A variety of Rhyolite

Uncommon
Thunder Egg specimen

What is Thunder Egg?

The Thunder Egg is a geode-like structure of different minerals, usually in crystalline forms, layered together into a solid structure. The outside is normally an ordinary dull gray or brown rock over a layer of brown or red rhyolite, but the inside can contain concentric rings and layers of quartz crystal, chalcedony, agate, and even opal.

Market Value Factors

Pricing varies for every rock and mineral, so use these universal factors to gauge Thunder Egg before comparing listings or appraisals.

Size & Weight

Larger, intact specimens usually command higher prices.

Rarity & Demand

Scarce material or popular varieties sell at a premium.

Condition & Finish

Chips, repairs, and heavy wear lower value; clean prep helps.

Treatment & Provenance

Untreated specimens with documented locality are prized.

Applies to all rocks & minerals.

Thunder Egg Localities Map

See where Thunder Egg is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview
North ZoneCentral RidgeSouth Basin

Interactive map layers and collecting notes are available in the app.

Key Characteristics

Composition of Thunder Egg

Rhyolite, Agate

More Images

Thunder Egg specimen
Cacophony
Thunder Egg specimen
Lech Darski
Thunder Egg specimen
Thunder Egg specimen
David Rix Eibonvale

Quick Facts

Physical Properties

Hardness (Mohs)
6 - 7
FREE APPTrusted by rockhounds
Ruby Glint rock identifier app

Identify Thunder Egg Instantly

  • Snap a photo, get instant results
  • 6,700+ rocks, minerals & crystals
  • Discover collecting spots near you

Thunder Egg FAQs

How do I identify Thunder Egg?

Thunder Egg can be identified by its hardness of 6 - 7 on the Mohs scale. Look for these key characteristics when examining specimens.

How hard is Thunder Egg?

Thunder Egg has a hardness of 6 - 7 on the Mohs scale. This gives it moderate hardness.

What is the composition of thunder egg of Thunder Egg?

Rhyolite, Agate

Related Rhyolite

Explore More Rocks & Minerals