UTAH (ABC4) – Did you know Utah has a state gem? 

According to the Utah Geological Survey, topaz has been Utah’s state gem since 1969. 

Topaz is a semiprecious gemstone that is most easily spotted by its hard, transparent crystals in a variety of colors.

The Utah Geological Survey shares that topaz can be found in Beaver, Juab, and Tooele Counties, with larger crystals and clusters sitting within cavities of white rhyolite in Topaz Mountain in Juab County, Utah.

Courtesy: Utah Geological Survey, Topaz Mountain in Juab County, Utah

“It is an aluminum fluorosilicate that forms from fluorine-bearing vapors given off during the last stages of cooling and solidification of siliceous igneous rocks. Naturally occurring topaz comes in a spectrum of colors, although it is commonly irradiated or heated to enhance optical properties. In the Thomas Range of western Utah, topaz occurs in cavities in rhyolite bedrock that bear the sought-after rich sherry-amber topaz. When exposed to sunlight, these alter to rose-pink or to a clear, silver-white color. Due to its beauty and hardness — the hardest of all silicates — topaz is used primarily in jewelry,” as stated by the survey.

The topaz crystals at Topaz Mountain are naturally amber colored, but become colorless after exposure to sunlight.

According to the Utah Geological Survey, the crystals formed within cavities of the Topaz Mountain rhyolite, a volcanic rock that erupted around six to seven million years ago (Tertiary Period) from volcanic vents along faults in the area.  

Topaz is not the only mineral that can be found in Topaz mountain. The survey says other minerals like red beryl, amethyst, garnet, pseudobrookite, bixbyite, opal, and hematite can also be found within Topaz Mountain. 

Mark Milligan, geologist for the Utah Geological Survey, tells ABC4 if you go to Topaz Mountain and are able to find some topaz, you can take it home with you. 

He says topaz at Topaz Mountain is found in holes, little cavities within an ash flow deposited from an erupted volcano. From the cavities the topaz formed, Milligan adds. 

Milligan says you can “collect topaz as long as you are not going to resell it.” He says the area of Topaz Mountain that is owned by the Bureau of Land Management (BLM) has been specifically set aside for “rockhounders,” or collectors. 

The BLM area of Topaz Mountain will not allow a commercial permit to be obtained. A permit has to be obtained to collect topaz, or any other material on the state lands side, but the BLM wanted resident and visitor collectors to be able to collect the beautiful mineral. 

Milligan says if you head to Topaz Mountain, chances are you will be able to find some topaz, especially on a sunny day when the sun hits the crystals and makes them shine. “They are usually pretty easy to pick up,” Milligan shares. 

“Single colorless topaz crystals can be found in the washes around Topaz Mountain. Crystals are usually less than an inch long,” as stated by the Utah Geological Survey. 

If you are looking for higher quality topaz, you may have to look harder to find some, Milligan adds. 

As a reminder, you cannot collect on marked claims.

Rockhounding can be a potentially dangerous hobby. To minimize the risk of injury, the Utah Geological Survey recommends you follow these safety tips:

  • Wear protective equipment
  • Do not work alone, and let someone else know your schedule
  • Carry a first aid kit
  • Watch for others, and when on slopes, never work directly above or below anyone
  • Do not enter abandoned mines or shafts

Remember, it is a privilege to collect Utah’s rocks, minerals, and fossils. All collectors must adhere to rules and regulations established by owners or managing agencies of the lands on which they wish to collect.

Prior to collecting, you should determine ownership of the lands you intend to visit and familiarize yourself with the regulations that apply to collecting on those lands.

“Utah’s lands are managed by the federal government (Bureau of Land Management, U.S. Forest Service, National Park Service, Bureau of Reclamation, Department of Defense, U.S. Fish and Wildlife Service, American Indians), state government (School and Institutional Trust Lands Administration), and private owners (including local governments). Rockhounding permits may be required to collect on some government lands, and permission is required to collect on private lands,” as stated on the Utah Geological Survey’s website.

See a full list of the Utah Geological Survey rules for rock, mineral, and fossil collecting rules.