This book takes readers on an intriguing journey to uncover the mystery behind the Coso Artifact, an ancient artifact discovered in the Coso Mountains of California. Through interviews with experts and detailed research, the author pieces together the history of the artifact and its possible origin.
From Wikipedia
The Coso artifact is an object falsely claimed by its discoverers to be a spark plug encased in a geode. Discovered on February 13, 1961, by Wallace Lane, Virginia Maxey, and Mike Mikesell while they were prospecting for geodes near the town of Olancha, California, it has long been claimed as an example of an out-of-place artifact. The artifact has been identified as a 1920s-era Champion spark plug encased in a concretion.