Front:
Champion Spark Plug Company Mine, Mono County, California
Back:
Many years of zealous research disclosed the fact
that Sillimanite could be used to make a superior
spark plug insulator. Then came the arduous task
of prospecting for the mineral. Champion engi-
neers found a huge deposit, millions of tons, high
in the Inyo Mountain Range, in Mono County,
California. It is the only commercially usable de-
posit of Sillimanite in the world. Only Champion
can use Sillimanite, the finest material known for
the manufacture of quality spark plugs.
