Our adjoining neighbor, the state of Idaho, is a fascinating area to explore for treasure and gemstones.
"Idaho is truly the “Gem State”. Since the origin of the earth, geologic processes combined to make the rocks of Idaho a mineral collector’s storehouse. This, coupled with the beautiful forests and streams, makes Idaho the place where the rock collector’s dreams come true.
Idaho offers the collector vast areas where precious and semi-precious stones can be found. Many of the collecting areas in Idaho have received international fame because of the beautiful material that can be found with very little effort. Many areas are so remote that they have not yet been exploited to any great extent. Agate, jasper, opal, agatized and opalized wood are found associated with the great lava flows in the southern part of the state. The northern part of the state has aquamarine, diamond, ruby and garnet. In fact, there is hardly an area in Idaho in which the rock collector cannot find rocks or minerals that will make his eyes light up.
In Owyhee County there are areas that yield red, yellow, green and mossy jasper of unexcelled quality. The area is nation-ally known for its pink and white plume agate and for its opal, both common and fire, which occurs in vesicles in the volcanic rocks. Banded, scenic, dendritic and sagenitic agates, as well as polka dot, smoky and moss agates are also found. Succor Creek on the western edge of the county yields red and green agates in a rich two-tone combination and a round shaped nodule, which is called “thunder egg”. These are often found to be geodes with the center filled with fluids. In some the hollow center is lined with quartz crystals.
In Gem County fire opal is found in the lava beds of Squaw Butte near Emmett. The opals are salmon pink or cherry red in color and display great brilliance. Most are very small, but some have been large enough to cut into fine stones. Near the opal deposits agates of light blue color abound. Willow Creek has deposits of agatized and opalized wood of high quality as well as massive opal that ranges in
color from deep red to salmon pink to white and pale blue.
In Washington County agates of many colors abound. The most highly prized agates are those that show an iridescence when cut into thin slabs. Petrified wood from Mann Creek northwest of Weiser is particularly beautiful. The grain of the wood is very prominent and the color is yellow, resembling natural oak.
In the Beacon area west of Weiser the famous “Beacon Hill” nodules abound. These nodules
are particularly beautiful because of the scenic or dendritic patterns. In some the interior is hollow and crystal lined.
In Adams County rubies and pink garnets are found at Rock Flat near New Meadows. Several diamonds have been found in this same area. Sapphires and corundum crystals that sometimes show asterism also have been found in the Rock Flat area.
In Custer County clear quartz, amethyst and citrine are found. Large geodes are common. Banded, red and yellow agate is scattered over the area. A forest of petrified wood is near Challis. Near the East Fork of the Salmon River is an excellent collecting locality where a variety of cryptocrystalline quartz is found in blood red sandstone. Near Challis a rare zeolite is found in greater abundance and
better specimens than in any other known locality.
In Latah County common and fire opals have been found in the vesicular basalts. The internationally famous garnet diggings on Emerald Creek afford the collector an opportunity to find gem and star garnets in remarkably large sizes and quantities. Fossil plant remains can be found in many localities in the siltstone of the interbeds between basalt layers.
Amethyst is found near Hailey in Blaine County. Opal and opalized wood can be found in Lincoln, Gooding and Boundary Counties.
Nationally famous flora beds are near Whitebird in Idaho County, and internationally famous “horse” fossil beds near Hagerman in Gooding County. Copper, silver, lead and zinc minerals are abundant in Shoshone, Blaine, Custer and Lemhi Counties.
The Idaho Geological Survey has publications for sale that describe the geology and mining history of many mineralized areas in Idaho. The collector will find the publications a help in researching for Idaho minerals. Publication inquiries can be forwarded to:
Idaho Geological Survey
University of Idaho
Morrill Hall, Third Floor
P.O. Box 443014
Moscow, Idaho 83843
Telephone (208) 885-7991
Other publication that might be of interest to the mineral collector is Gem Minerals of Idaho by John A. Beckwith, Idaho Minerals by Lanny R. Ream and The Minerals of Idaho by Earl V. Shannon."