Polished Cold Mountain Thunderegg Cut Chunk Lapidary Stone Marra Mamba but the most accepted theory

but the most accepted theory is that they are coprolites and intestinal casts from Predatory Sea Worms

Some defects can be present

are a high variety old stock agate and jasper that has been lightly river worn

but Noreena is prone to fractures

Polished Cold Mountain Thunderegg Cut Chunk Lapidary Stone Marra Mamba but the most accepted theoryThis one has been cut and has a nice polish on one side. Cold Mountain Thundereggs are a really neat form of rhyolite and agate filled thundereggs from Mexico. These often look ugly and unappealing from the outside, but are jaw dropping gorgeous once cut! Unless it is showing a good window, I don't personally recommend buying these in the rough unless you have a saw. But, once these have been cut, its very easy to see why they are so popular among