We often receive questions about Utah’s state symbols, especially those that concern the state mineral (copper), rock (coal), and gem (topaz). Most of these inquiries are from people who live outside the state and are planning Utah rock-and mineral-collecting vacations.
Minerals: Minerals are naturally occurring inorganic elements or compounds that have an ordered internal structure and characteristic chemical composition, crystal form, and physical properties. For example, quartz is a mineral as is copper.
Rocks: Minerals combine to form rocks like granite, basalt, and sandstone. Rocks can also be composed of solid organic matter, coal is an example.
Gems: Gems are especially fine (“gem quality”) mineral specimens that have few flaws in their internal structure and exhibit superior color. These high-quality minerals are typically cut and used in jewelry.
Copper, Utah’s State Mineral
Utah’s state mineral, copper, is versatile and widely used due mainly to its conductive properties (heat and electricity). It is used in electronics, plumbing, transportation, and in alloys (a mixture of two or more metals).
Most of the copper mined in Utah comes from Kennecott’s Bingham Canyon mine in the Oquirrh Mountains on the west side of the Salt Lake Valley. The Bingham Canyon mine is the world’s largest open-pit copper mine, measuring 0.5 miles deep and 2.5 miles wide. For perspective, the world’s tallest building, the Sears Tower, is 1,454 feet tall and would reach only half way up the side of the pit. The mine has produced 12 million tons of copper since open-pit operations began in 1906. This production figure is eight times the total metallic mineral yield from the Comstock Lode, Klondike, and California Gold Rushes combined. The Bingham Canyon mine is an important contributor to Utah’s economy.
Coal, Utah’s State Rock
Coal, Utah’s state rock, originates as plant matter that accumulates up in wetlands and bogs. Coal begins to form when anaerobic bacteria break down plant material and convert it to peat through the removal of oxygen and hydrogen. The peat is then buried by sediment and more plant material, raising the temperature and pressure of the peat. As the peat compresses, water and methane gas are forced out, leaving an increasing proportion of carbon. With increasing heat and pressure the peat is converted successively into lignite, subbituminous coal, bituminous coal, and anthracite. Most of the coal mined in Utah is bituminous.
Coal is used during the coking process in steel production, and is burned in power plants to produce heat and electricity. Over one-half of the electricity used in Utah is generated by coal burning facilities. Coal is found in 17 of Utah’s 29 counties, but coal mining is primarily concentrated in Emery and Carbon Counties. Coal production in Utah during 1994 is estimated at 24 million tons.
Topaz, Utah’s State Gem
Topaz, Utah’s state gem, occurs in cavities in the rhyolites of the Thomas Range of western Utah, and is found in a variety of colors (for example, pink, violet, yellow, green, blue) or may be colorless. Due to its durability and beauty, topaz is used primarily in jewelry. For information on where to collect topaz in Utah, refer to “The Rockhounder, Topaz at Topaz Mountain” article.