The dugways of western Utah are a geode thunderegg. Most dugways are hollow; a much higher percentage than any other thunderegg exposure. Most have a blue tint with the best having a sparkly quartz druze. There are lots of holes dug all over this area with one claim where a large back-hoe resides. Owned by a rock shop in Delta (the Bug House) it is a working mine with a big (Stay Out) pit. Permission to dig here is highly recommended and easy to obtain. The fee is 30 bucks and a waver needs to be signed. I spend most of my time digging in the thunderegg exposure furthest north just 1/2 mile past the claim. There are lots of diggings at the south entrance to this area but I have had little luck in those areas. I like to dig in the perlite (in Situ) and in the north bed, veins of thundereggs can still be found. It takes a day of hard work just to clean out a hole and get to the vein.
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The north diggings looking out over the south end of the Great Salt Lake Desert. the first picture was taken in 2010 and is way out of date. In 2012 this area was worked by the claimant with the blessing of BLM to take off some of the pressure the claim was getting by rockhounds who were not paying the fee and more importantly not signing the waver. the second picture was taken in 2014 and to say the least there has been some digging going on here.
Cleaning out a hole. I hit the floor of the old dig and found the perlite vein with the thunder eggs (white layer).
The eggs are rotten to the right, but to the left and down the perlite is soft and the eggs are good. By rotten, I mean the eggs have been exposed to near-surface freezing and are partially decomposed and the insides compromised.
Time to muck out the overhang before I am crushed. This area is especially bad for undercutting and you must be diligent in making sure you are not buried alive. That big rock weighs more than me and no egg is worth a snapped leg or worse.
Lots of rotten geodes. These have been exposed to freezing and are badly fractured. Worthless to saw, but they still can be pretty specimens.
Working off the overhang. Every digger has their own method. Mine is the "bad back" method.
Tailings are a bitch. I had to build a rock wall to hold back the overburden. If only I worked this hard in my garden.
Several nice eggs. I must be careful not to break the eggs with my pick, so a screwdriver is helpful to find the fragile eggs in the soft perlite mud.
At least there is shade. You have heard of rockhounds digging their own grave. If I don't soon clean off the overhang, mine will be dug.
Nice one! The vein dips down and the digging gets harder. Notice the flow banding of the perlite. This is not an erosional bed. It is a perlite flow similar to all the thunderegg exposures elsewhere. I see no evidence that the Dugways were moved by waves of an ancient lake as I have read. Only a very small percentage of these eggs would be able to take the punishment of that kind of action as most are very fragile.
A day's work (play) is around 75 pounds of geodes.UPDATE:
I made a trip to the dugway beds in March 2014 and made my way to the north bed to try to find a vein of big thundereggs. It was a nice day with sunshine and 55 degrees, but the digging wasn’t so good. The few big eggs I uncovered were full of dirt and ugly, and the nice desert quiet I was enjoying was broken up by a very chatty couple of older rockhounds. They just wouldn’t be quiet, and yelled at each other from across the pits as though what they were saying was important (it wasn’t). I was so glad when they drifted far enough away from me that I could not make out what they were saying. After a few hours of futile digging went by, I heard this couple talking louder and could make out the words... 'wow' and 'there is another one', so I snuck over to the pit they were digging in to see what the excitement was about. Well... this noisy couple had found a vein of thundereggs tucked in beside a solid rock hanging wall that had protected the vein from the backhoe. I had checked out the pit they were in earlier but did not spot this vein, hidden so nicely up under the solid rock. The altered perlite that contained the thundereggs was very soft and even with inadequate tools and limited abilities of this couple (in their eighty’s they told me) they were digging some major thundereggs. They were getting tired though and the day was almost over so I knew there would be eggs to dig the next day. It was almost sundown when they quit digging and loaded up their buckets full of thundereggs to make the long trip home. I was the only rockhound spending the night at the beds so I set up camp a few feet away from the vein and went to sleep knowing the next day would be special. The next morning I went right to work. I had to remove all the overburden created by the previous rockhounds so I could see just how wide and deep this vein went.
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The thundereggs in this vein were very nice. The size varied from grape to softball, and the interiors were very gemmy blue and purple quartz. I did hit one pocket of nice thundereggs with a single large 10 inch egg in the middle. Unfortunately this egg broke on extraction showing a sparkling brown and blue quartz lining. It was a triple egg that would have been fantastic if it had held together for the saw.
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