Approximately 100 miles west of where we live in Riverton, Utah
, out in the Utah desert lie the Dugway geode beds.
Six to eight million years ago volcanic activity occurred in western Utah and deposited an extrusive igneous rock called rhyolite. Trapped gasses
formed cavities within the rhyolite, and millions of years of ground-water circulation allowed minerals to precipitate into the cavities. The resulting geodes have roughly spherical shapes and (hopefully) crystal-lined cavities.
For a period of as long as 20,000 years ago starting 30-35 thousand years ago, an inland body of water known as Lake Bonneville covered most of western Utah. The lake's wave activity eroded
the geode-bearing rhyolite and redeposited the geodes several miles away in the Dugway geode bed area as lake sediments.
The geodes I’ve found are in very interesting white clay which is veined with purple strips (look closely at the second picture).
Many geodes are hollow
while others are completely filled with massive, banded quartz or, worse yet, turn out to be mostly rheolite. The most common mineral deposited inside the geodes is quartz in various colors: clear (rock crystal), purple (amethyst), and pink (rose).
Dugway is particularly known for blue colored quartz.
It's kind of hard to
figure out what you've got when you dig them up because they're all covered with clay. And often you break them either when you are digging or when you are trying to get them out as they often have seams in them that split, or weak sides, etc. But every once in a while you get a
good one like the one shown in the third picture that is relatively large. The most typical ones are more in the range of two to six inches. Once you find them, it's like Forest Gump's box of chocolates: you never know what you are going to get until you cut them open. Sometimes its a pleasant surprise and other times it's "oh well".
COE, let me know.
I just got a hold of Mom's camera so will post a few more of Clark's pictures. Don't ask why he wasn't in the basement. He just said it was so "calm" outside. You should be able to see the hail falling in a couple of these. Guess there wasn't any rain.
There was just a little excitement in Divide County on Monday. This is a picture Clark took at Mom's standing right in front of the house. I guess there were 3 funnels lurking around at one time. I think it was this one that I saw from the highway on my way home from Williston. I didn't even realize there were tornado warnings and looked to the east only after I saw a farmer jump out of his tractor and look at the sky. I could see that it was picking up dust as I picked up speed :-). I guess Loring Johnson (2-3 mi. NW of Mom's) had a storage building roof blow off and a windbreak (fence) blow down. You can see lots of pictures of several tornadoes spotted around the area on kxmd.com under weather and weather photos. It was a real muggy and hot day, strange weather!
OK cousins -- my theory on why Hagens love rocks, is that our Dads spent their youth picking rocks out of the fields to make room for crops. Here is a picture of a place that all rock lovers would find great delight: mainly the red rocks of Sedona, Arizona. It is worth a trip to go there, and dont' miss the Red Rocks Pink Jeep tourn. It costs a pretty penny and is worth every bit of it. Sedona is one of my favorite (if not my very favorite place) that I've ever visited.
, out in the Utah desert lie the Dugway geode beds. Six to eight million years ago volcanic activity occurred in western Utah and deposited an extrusive igneous rock called rhyolite. Trapped gasses 
formed cavities within the rhyolite, and millions of years of ground-water circulation allowed minerals to precipitate into the cavities. The resulting geodes have roughly spherical shapes and (hopefully) crystal-lined cavities. For a period of as long as 20,000 years ago starting 30-35 thousand years ago, an inland body of water known as Lake Bonneville covered most of western Utah. The lake's wave activity eroded 
the geode-bearing rhyolite and redeposited the geodes several miles away in the Dugway geode bed area as lake sediments.
while others are completely filled with massive, banded quartz or, worse yet, turn out to be mostly rheolite. The most common mineral deposited inside the geodes is quartz in various colors: clear (rock crystal), purple (amethyst), and pink (rose). Dugway is particularly known for blue colored quartz.
figure out what you've got when you dig them up because they're all covered with clay. And often you break them either when you are digging or when you are trying to get them out as they often have seams in them that split, or weak sides, etc. But every once in a while you get a
good one like the one shown in the third picture that is relatively large. The most typical ones are more in the range of two to six inches. Once you find them, it's like Forest Gump's box of chocolates: you never know what you are going to get until you cut them open. Sometimes its a pleasant surprise and other times it's "oh well".
