Rare Gems and Minerals in Wisconsin

Wisconsin shares its coastline with two of the Great Lakes, Lake Superior and Lake Michigan. The state of Wisconsin is famous for its vast deposits of iron ore, but for rockhounds there are other minerals that are more interesting. Some of the gemstones and minerals that are common in the state are the Lake Superior agate, calcite, quartz and malachite. Michigan isnít the best state for fossil hunting, but there are a few types of fossils have been found in the state.

Lake Superior Agate

Lake Superior agate that occur in orange, yellow and red colors and were formed as a result of the volcanic activity that took place in the United States billions of years ago can be found at various beaches close to the shoreline of Lake Superior. One such location in Wisconsin is that of Saxon Harbor Beach on Lake Superior in Iron County. Another location where Lake Superior agate can be found is at the Apostle Islands located on the northern end of Wisconsin on the shoreline of Lake Superior.


Calcite is a commonly occurring mineral throughout the state of Wisconsin and can be found in many counties at various mines. Some of the locations that are known to have calcite crystals are the Blackstone Mine and the Eagle-Picher Mine situated in the Shullsburg District of the Lafayette County, at the Montreal Mine and around Platteville in Grant County, and various locations in Milwaukee, Racine, and Iowa Counties.


Quartz is a widely found mineral throughout the state of Wisconsin. The quartz crystals that are found in Wisconsin occur in various forms and colors. Reddish brown and molted variety of quartz also known as zebra sandstone can be found in the Jackson County. Other locations where quartz can be found in Wisconsin are at the William Quarry in Columbia County, and locations in Grant, Saul, and Juneau Counties. At some of these areas the quartz are found in colors such as pink, green, grey and milky.


Malachite is a mineral that is composed of copper carbonate hydroxide which is found in a bright green hue and is used as a gemstone. Malachite found in Wisconsin are found in various forms such as coils, fibers and in globular shapes. The numerous copper mines situated throughout the state are a source of malachite found in Wisconsin.

There are many copper mines that are associated with malachite deposits. Many are located in Crawford, Douglas, and Iowa counties. Other deposits of malachite have also been found at mines in Forest, Grant, Green Lake, Polk, and Rusk counties.

Copper Nuggets and Specimens

There have been copper nuggets found all throughout Wisconsin. Although they are not nearly as plentiful as those found in Michiganís Upper Peninsula, there are many that have been found ranging in size from small nuggets to huge boulders weighing thousands of pounds.

Some of the copper specimens are found associated with the deposits found in Bayfield, Washburn, Douglas, and Polk counties, but much of it was probably brought to Wisconsin by glacial drift, the same glaciers that moved gold throughout the Midwest.

Douglas County has the most copper deposits in Wisconsin. Copper is found as both rounded nuggets and coarse crystalline specimens.


Calymene celebra was declared as the official state fossil of Wisconsin in 1986. This is a type of trilobite that lived in shallow sea water within the reefs to feed itself. Calymene belonged to the late Silurian and Ordovician eras that existed about 460 million years back. The calymene calebra were of a similar species of that of crabs and insects and their bodies were segmented, that had jointed appendages with an exoskeleton. The fossils of calymene celebra can be found in the southern region of Wisconsin where dolomite and limestone deposits occur.