State Rocks, Minerals, and Gems


State mineral: gold

Gold can be found and mined throughout Alaska, and has always been a major state industry and force for exploration.

State gem: nephrite jade

Large deposits of this green metamorphic stone are found throughout the Seward Peninsula. It formed during accretion of the area’s terranes.


State mineral: gold

California’s nickname is the “Golden State.” Its early population expansion and modern development, including roads and infrastructure, can be traced back to the discovery of gold there in 1848 and the ensuing gold rush.

State rock: serpentine

This green metamorphic rock is found throughout California’s Coast Ranges, Klamath Mountains, and Sierra Nevada foothills. It formed through the metamorphism of oceanic peridotite during subduction.

State gem: benitoite

Benitoite is a rare blue fluorescent mineral formed when serpentine undergoes metamorphism.


Hawai’i has no state rock. The designated state “gem” is black coral.


State mineral: silver

Nevada’s nickname is the “Silver State,” dating back to the silver rush of the mid- 1800s. In some areas, silver had weathered out of desert rocks over millions of years, and could often be shoveled right off the ground. Within a few decades, the desert had been picked clean of these silver deposits.

State rock: sandstone

Sandstone is found throughout the entire state of Nevada and makes up some of its most spectacular scenery. The State Capitol Building is even built of sandstone.

State gem: black fire opal

These gems are found in layers of clay that formed when a volcanic eruption filled an ancient lake. Silica in the ashfall replaced the cells and cavities in buried wood, hardening over time into opal.


State rock: geode

These geodes, locally called “thunder-eggs,” are found in Eocene-age rhyolite lava flows, having formed within gas pockets that served as molds.

State gem: Oregon sunstone

This type of translucent feldspar formed as large crystals in basaltic lava flows.


Washington has no state rock. The designated state “gem” is petrified wood.