Thunderegg
12 August 2025
Description
Thundering geode- rare formation. From the closed mine in Madras, OR
Dimensions
10x9
Acquired from
Inherited
Inherited
For sale
Yes
Yes
Answered within
2 days
By Amber R
Aug 14, 14:47 UTC
The specialist needs more information
Hi, Maria,
I believe this to be Barite, a mineral composition of barium sulfate. The formation occurs in various forms, including crystals and within petrified wood. Barite can be found within some thundereggs, sometimes exhibiting UV fluorescence.
From images, I cannot tell if you have a partial section of the full geode. Please let me know and the full example will yield a higher FMV.
Amber r
Aug 15, 14:07 UTC
Thank you for the additional images and information, it all helps to add some context to what I am looking at.
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Hello,
I did have some specialist look at it but due to their organization they could not provide an appraisal. They believe it is Calcite or Aragonite, or plume agate. I do have the full geode. I actually have 2 full geodes that look like this. I'll add some pic's of what I have. This geode is in 3 pieces- there is one piece that does not have a lot of the same features.