Oakley stone is the trade name of a building stone that occurs in the mountains of

southern Southern may refer to: Businesses * China Southern Airlines, airline based in Guangzhou, China * Southern Airways, defunct US airline * Southern Air, air cargo transportation company based in Norwalk, Connecticut, US * Southern Airways Express, M ...

Idaho in the western United States. It is more properly known as Rocky Mountain quartzite or Idaho quartzite, a metamorphic rock. The stone is

quarried A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some juri ...

south of the city of Oakley in

Cassia County Cassia County is a county in the U.S. state of Idaho. As of the 2020 Census the county had a population of 24,655. The county seat and largest city is Burley. Cassia County is included in the Burley, ID Micropolitan Statistical Area. History ...

, northeast of the three-state border with Nevada and Utah. The quarries are located on the west slope of Middle Mountain in the Albion Mountains, northwest of the

City of Rocks National Reserve The City of Rocks National Reserve, also known as the Silent City of Rocks, is a United States National Reserve and state park in south-central Idaho, approximately north of the border with Utah. It is widely known for its enormous granite ro ...

. Oakley stone is micaceous, meaning it is a

mica Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is ...

-bearing stone. This mineral gives the product a fish-scale-like sheen. The stone is noted for its great variety of colors, ranging from white and silver to browns, yellows, and golds. Another stone in the area, Elba Quartzite, is a green micaceous quartzite. The green color of the rock is the result of

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

in the mica which is also known as

fuchsite Fuchsite, also known as chrome mica, is a chromium (Cr) rich variety of the mineral muscovite, belonging to the mica group of phyllosilicate minerals, with the chemical formula . Trivalent chromium replaces one of the aluminium (Al) atoms in the ...

. The original sedimentary rock from which the quartzite formed was a quartz-rich sandstone. During the metamorphic process, the pressure caused the layers of clay within the sandstone to thin and flatten into the mica-rich layers. The space between planes of parting or foliation are consistent which makes it uniform in thickness. The outcroppings of the stone usually lie parallel to the ground and occur in large plates that can be easily split into thin veneers. Beginning in 1948, the stone was mined and sold in large quantities throughout the United States. It used for interior decoration, fireplace mantels, decks and patios, or facing buildings. A variant is "builders" which are naturally occurring

brick A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...

-shaped pieces used to face building exteriors, building property walls, or fireplaces. There are about a dozen companies in the Oakley area quarrying the stone. Archie Boyd Teater's

Studio A studio is an artist or worker's workroom. This can be for the purpose of acting, architecture, painting, pottery (ceramics), sculpture, origami, woodworking, scrapbooking, photography, graphic design, filmmaking, animation, industrial design ...

Geography

The staging area for quarried Oakley stone is located at (42.139, -113.89), at an elevation of above sea level. The quarries are to the east and Middle Mountain is to the southeast, with a summit over .

References

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External links

Idaho State University
- Idaho Museum of Natural History - quartzite
Mini Cassia Chamber of Commerce

- Oakley stone quarry
Southern Idaho Living.com
- Oakley Rocks - May 2008 Geology of Idaho Metamorphic rocks Quartzite formations