A field guide to Topaz and associated minerals of the Thomas Range, Utah (Topaz Mountain) volume 1
If you ever take one rockhounding trip, this one is a must: Dugway Geodes and Topaz Mountain. My cousin Tom has some kids who have become interested in rocks, so we thought this would be a fun trip. We hopped in the van around 6:00 am and headed out around Utah lake on hwy 73 and watched as the sun rose over the hills. We drove through Faust to Vernon, and then the pavement ended. After that it's desert and jackrabbits. We headed up over Lookout Pass and enjoyed the view before descending into the west desert.
The dirt road you take is actually the Pony Express route used in 1858 to carry the mail. You can visit the Pony Express stations along the way. We stopped in Simpson Springs for a break and checked out the little cabin. Time seems suspended out there; you can almost imagine what it was like for the guys running the outposts--living in the middle of nowhere with a couple of horses and waiting to get scalped by the locals. But the view was nice and the kids broke of some weird green tuff near the monument.
From there you drive along the edge of the Dugway Proving Ground: this place is straight out of a Tom Clancy novel--they test all kinds of war toys out here. Not a nice place to venture into (not that you'd get far -- the snipers would probably shoot you first). I have a friend who's a firefighter, and they dropped him by helicopter into a brushfire in Dugway once. He said he wandered over a ridge and saw a bright green pond.
We followed the Pony Express road for another 20 miles and turned south just before the Dugway pass to go to the Topaz ampitheatre. We followed the Pismire wash for 15 miles along the east side of the Thomas Range until we came to the Weiss Highway and turned into Topaz Valley.
Once you're in the valley you can pretty much pick a spot and start looking for crystals. The whole mountain range is made of rhyolite that formed with huge gas pockets in it. You find a crack and pry it open with a crowbar. The inside will be filled with sand and crystals. You can also look in the dry washes for clear topaz crystals. We opted for the tried and true location - the west side. Just walk up the side of the mountain and start looking in the cracks. We pulled out a handful of clear topaz and a few specimens of the sherry-colored stuff. It's really nice to look at, I must say. You can also find what they call clinkers. They are topaz that is so included with quartz that it becomes opaque.
I was having a blast, but some of the kids were starting to get whiny and fighting over the crystals, so we decided to go somewhere a little easier. We headed out of the ampitheatre and drove a few miles up the west side of the Thomas Range to a collecting site for Apache Tears. You drive up a small canyon and pretty soon the ground is littered with obsidian and jasper pebbles. Apache tears are little round pebbles of black volcanic glass. You can also find mahogany obsidian, which has brown streaks in it. I climbed around in the hills and found some wild rocks - bright red and pink matrix with black obsidian in them. After 20 minutes or so we were done there. We hopped back in the car and drove north through the Dell.
I was salivating over all of the mine dumps I saw, but we had to get to the Geode Beds so we kept driving. The Dell is a scenic place to be; many mining operations (even a Deseret mine. Hmm). Eventually you come around a bend and descend onto the edge of the salt flats. We're talking edge of the world here; it's an amazing feeling. You really feel exposed out there--it's so flat you can see the curvature of the earth. Soon we hit the Pony Express road and a few miles later turned off at the geode beds.
My hat is off to Loy Crapo. He bought the claim and maintains it for collectors. He periodically digs a new pit with his backhoe when collectors have exhausted the previous one. The minute you drive up to the site you can see piles of geodes left by the previous collectors. If you go on a Saturday you might see up to a dozen other collectors, but everyone is friendly. Just walk right into the pit and claw them out of the clay. If you are lazy you can paw through the piles of geodes around the sides of the pits. Just be careful you don't fall in. As collectors dig further into the sides of the pit, there is a risk for minor cave-ins.
The geodes here are usually filled with a blue or white chalcedony, with layers of black or white quartz crystals. I have heard of amethyst and barite being discovered in some of them. If you find a nice large one, resist the urge to break it with your hammer to see what's inside. Go to a rock shop and pay them a few bucks to saw it open for you. It's worth the wait.
We gathered as many geodes as we could. The clay they are found in is pink and yellow, and bears a striking resemblance to refrigerated cookie dough. I was getting hungry. We gathered the troops and sorted through our haul, discarding some of the finds for the next guys who came around, and headed back to the road.
I always have a strange feeling reentering civilization after a trip into the desert. The trip out there feels strange, because every hill you pass over becomes more and more desolate. After a day out there I adjust to the peacefulness and find myself feeling more anxious as I can see the city again. It's an interesting transition. I usually end up wishing the next trip were sooner.