Mariposite

“Gold country's green companion”

Metamorphic

Mariposite is a chromium-rich variety of muscovite mica that gives metamorphic rocks a distinctive vivid green color. It's closely associated with California's Gold Rush country, where green mariposite-bearing rocks often signaled nearby gold-bearing quartz veins.

Composition

chromium-bearing muscovite, quartz, albite, chlorite

Where Found

Mariposa County (California, USA), Mother Lode Belt (California), similar occurrences in British Columbia (Canada)

Mohs Hardness

3-4

Fun Fact

Gold Rush miners in the 1850s quickly learned that the bright green mariposite-stained rocks in the Sierra Nevada foothills were a reliable sign that gold veins were nearby.