Topaz became the State Gemstone of Utah in 1969, when the State Legislature finally made a decision since so many different gemstones can be found among the State's Rhyolite formations: Quartz, Hematite, Bixbyite, Garnet, Pseudobrookite, Amethyst, Cristobalite, Durangite, Cassiterite and Red Beryl in the cavities of Rhyolite formations along the Thomas Mountain Range in Juab County. Topaz, occurs as very hard, transparent crystals in Beaver, Juab and Tooele counties.
.
But, Utah has a whole mountain named for the gemstone, Topaz Mountain located in the Southern most portion of Thomas Range.
It is characterized by light gray to white Rhyolite. The south eastern most point is Topaz Mountain Amphitheater, also know as Topaz Valley. This is the main and easiest accessible collecting area of the range. Topaz Valley was set aside by the B.L.M. Department of the Interior as a rockhound area. Despite rumors of it being completely picked over, with hard work and a lot of patience you are often rewarded with some fine clear or sherry colored Topaz. The Topaz crystals at Topaz Mountain are naturally amber colored, but become colorless after exposure to sunlight. The crystals formed within cavities of the Topaz Mountain Rhyolite, a volcanic rock which erupted approximately six to seven million years ago, Tertiary Period, from volcanic vents along faults in the area. If someone is looking for Blue Topaz, or other colors of Topaz, you won't find it here.
.
It is characterized by light gray to white Rhyolite. The south eastern most point is Topaz Mountain Amphitheater, also know as Topaz Valley. This is the main and easiest accessible collecting area of the range. Topaz Valley was set aside by the B.L.M. Department of the Interior as a rockhound area. Despite rumors of it being completely picked over, with hard work and a lot of patience you are often rewarded with some fine clear or sherry colored Topaz. The Topaz crystals at Topaz Mountain are naturally amber colored, but become colorless after exposure to sunlight. The crystals formed within cavities of the Topaz Mountain Rhyolite, a volcanic rock which erupted approximately six to seven million years ago, Tertiary Period, from volcanic vents along faults in the area. If someone is looking for Blue Topaz, or other colors of Topaz, you won't find it here..
Single colorless Topaz crystals can be found in the washes around Topaz Mountain, however the crystals are usually less than an inch long. Larger amber crystals or clusters of Topaz and the other gems and minerals listed above, can be found by breaking open the white Rhyolite to find cavities.
.
Topaz can be collected on BLM public lands, School Trust Land (state land) and possibly on some gemstone leases. Precautions should be taken when hunting for the Rhyloite Rocks, hoping to find Topaz inside. A four-wheel drive vehicle is recommended but not required for the last few miles of the journey. Do NOT collect on marked claims. Bring a rock hammer, chisels, and protective eyewear if you intend to break pieces of rock. A hat and plenty of water is recommended. 
Always be on the watch for rattlesnakes. If you feel like a 3000 ft climb, no roads or paths, some of the better materials can be found higher up in the mountain.
Always be on the watch for rattlesnakes. If you feel like a 3000 ft climb, no roads or paths, some of the better materials can be found higher up in the mountain..
Many times faceted White Topaz is used in place of Diamonds in jewelry creations.
.
Picture of Topaz crystals in Rhyloite from a mineral specimen from JohnBetts-FineMinerals.
.
.
