* Astronomy

The Coso Artifact is a spark plug found encased in a lump of hard clay or rock on February 13, 1961 by Wallace Lane, Virginia Maxey, and Mike Mikesell while they were prospecting for geodes near the town of Olancha, California, and long claimed as an example of an out-of-place artifact.
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Ed ~ It was not, as first assumed, a geode