“Mariposite” is an informal name that is most often used for green micas that are thought to be colored by small amounts of chromium. The name “mariposite” has also been used for a group of green and white metamorphic rocks that contain significant amounts of green mica. “Mariposite” has been used in many different contexts since the late 1800s.

The name originates from the community of Mariposa, California. Green mica and green rocks that derive their color from green mica are seen in a few spectacular outcrops in that area. During the California Gold Rush, many prospectors learned that mariposite rocks were often sources of gold. Looking for green and white rocks became a prospecting method that sometimes resulted in success.