Many Californians might think gold is the state rock, but in fact it is the state mineral. Since 1965, serpentine has been the State Rock, the first such designation for any state. The choice of serpentine was an economic one. Serpentine is a source of asbestos, which was widely used in construction and other industries. With more serpentine than any other state, California benefitted financially from this mineral. However, by the 21st century, it was well known that exposure to asbestos was dangerous to human health and so its use was reduced and limited.

Serpentine is named after the colors of a serpent: green, blue, and cream. Serpentine is often very smooth, slippery, shiny and fibrous and can be easily fractured. It is found from central to northern California in lower to mid-mountain ranges.

(Senate Bill 265, Chapter 89, 1965)