State Gemstone: Star Garnet (1967)
State Fossil: Hagerman Horse Fossil (1988)

Idaho’s nickname is ‘The Gem State.’ Originally suggested as the name for the land that became the State of Colorado, the name “Idaho” was used for a steamship that traveled the Columbia River. With the discovery of gold on the Clearwater River in 1860, the diggings began to be called the Idaho mines.

Idaho’s mountains have rich veins of silver and other metals such as gold, lead, and zinc. In addition to the state’s rich mineral ore legacy, Idaho has garnets, opal, agates, jasper, quartz, petrified wood, and a wide variety of fossils. The state also is home to an amazing variety of geological formations including large lava flows and Hell’s Canyon, the deepest canyon in the U.S.

In addition, five meteorites are known to have been found in Idaho!


Minnetonka Cave
Bear Lake County, Idaho  CLICK HERE
Minnetonka Cave, located in the Caribou-Targhee National Forest at the north end of Bear Lake in southeaster Idaho, is the largest limestone cave in Idaho. The cave features stalactites and stalagmites. Numerous fossils of animals that lived in the tropical waters of the Mississippian Period are found in the cave walls and ceiling. These fossils include: horned coral, honeycombed coral, brachiopods, bryozoans, and crinoid stems.

Star Garnets
Emerald Creek Garnet Area – Near Clarkia, Idaho CLICK HERE

Spencer Opal Mines – Spencer, Idaho CLICK HERE


Please note that rock collecting locations are always changing so be sure to check with the site owner for the most current information before going.

Dig safe, never go underground, and make sure to get permission from the landowner to search for and collect rocks.