The Coso Artifact is an OOPART (Out-Of-Place Artifact) discovered in February 1961 in the Coso Mountains near Olancha, California. It was unearthed by rock and geode hunters—Mike Mikesell, Wallace Lane, and Virginia Maxey—who ran the LM & V Rockhounds Gem and Gift Shop in Olancha.
This finding has puzzled researchers, as the concretion is estimated to be at least 500,000 years old, while spark plugs were invented in the 19th century. Some people who support alternative history and unusual theories believe this artifact proves advanced ancient civilizations or even time travel. However, skeptics think the concretion might have formed around the spark plug much faster through natural processes.
On February 13, 1961, the three people were searching for geodes to sell in their gift shop. They searched in Olancha, California, and brought their finds back to the shop to sort and cut. When one of the “geodes” was cut open, they found a metal and ceramic cylinder inside.
An X-ray clearly showed the metal pin, with a spring or helix at one end. The other half of the object showed metal covering the porcelain-like cylinder.
The Coso Artifact is now on display at the Pacific Science Center in Seattle, Washington.
No one can clearly explain how the spark plug got into such an ancient geode, so the artifact still interests many people who believe in lost knowledge or alternative history.