My good friend Linda Dodge has gone ’round the rock garden to take pictures of rocks and description signs I missed. She has also taken better pictures in many cases of rocks I had already photographed. 78 photos in total, of which I suspect at least twenty will be posted here. Time to start processing. Captions will take a long time to do.
Parking is expensive at U.C. Davis during the weekdays ($10!?) but you can use that parking pass all over campus. Have a picnic in the Shields Oak Grove where I volunteered for many years. All of the arboretum is first class.
They have a fine equestrian center and if you are quiet and not too suspicious looking, you can walk through the stables and consider whether you really want to own a Percheron.
Most campus buildings are probably closed to the public, but when they reopen there are a variety of places to eat. You don’t need to be staff or a student to eat at most of them.
There’s a science library, a law library, and a main library.
If you have a bicycle you will fit right in.
Updates
My friend the practicing geologist confirms that I indeed found leucogranite with altered garnet in the Utah Hill area and that it is suitable for study use. I go back to the area this week to look for a pegmatite pocket. Follow me on Instagram, that’s where I report on my field trips.
06-23-2020
Rolf Luetke has closed Sunshine Gifts and Gallery until further notice. Business is too slow because of the pandemic.
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I didn’t mention State Parks in my book very much because they don’t allow collecting. Still, I visited several and took many photographs that had no home. As I have said in previous posts, I am uploading the better ones to Wikimedia.
This one turned out well. A couple and their dog look down into the signature feature of the park, the so called Fire Wave. It’s a sandstone bowl, a confusion of swirls and layers and depressions. Like a crazy skate park might look if Fred Flintstone designed it.
This image would be better cropped, so that the couple are nearer. I didn’t do that, letting a user make their own decisions. Any editor wants the full image, as many pixels as possible. The original is 6,000 by 4,000 pixels, good enough for any magazine printing and even some decent enlargements.
If Wikimedia allowed posting RAW files then I would do that.
Here’s a 1,000 pixel size image at this site and then there is a link to the Wikimedia page where you can see that it is in the public domain and choose from a variety of download sizes.
I self-collected my first piece of sandstone yesterday in a desert wash near Las Vegas. It has two bullseyes which I think is extremely unusual. Most sandstone exhibits bedding or strata.
Here’s a single still picture below, then two videos. The rock is this picture is wet from my cleaning it; it looks better when dry.
My friend the geologist R.C. says. “The curved lines are liesegang banding, an iron oxide stain. It forms the picture rock like that sold in Kanab, just from a different rock formation.”
I have a piece of picture rock that has been heat treated to bring out the iron color. I bought that small slab two years ago. I show it in the second video.
Here’s a short vid with good color of my rock. I made it on the tailgate of my truck when I first found it.
This is a longer video with sound and indoor light. It’s a more informative video but the color of the rock is not so good. I am still learning about video.
Update: Just noticed that a piece of sandstone I bought at Vanderford’s Gold Strike in Goldfield, Nevada also exhibits orbs. Perhaps they are more common than I thought. Much to learn and notice. Let me know in the comments below if you have any bullseye sandstone.
Rolph’s Luetcke’s sends some pictures of his sandstone collection and shares some of his recollections on same.
Hi Tom,
Cool piece you found. I have some from Nevada and got those in a neat way. One trip up to Oregon to collect Obsidian and Opal back in the 70’s. One motel had a bunch of the picture rock lying in the weeds by the side of its property. The gal who owned the place happened to come out when I was looking at the stones and I asked her about them and she said she was sorry about that mess and she had meant to get someone to clean it up. I smiled and said I would be glad to remove them for her. She was so very happy to get rid of that junk. To some it is junk, to me it was treasure and free for the picking. I still have some of the pieces lying out in the back yard. Made some cabachons out of the material too and it worked up fairly nicely as you can see.
The next is from Arizona and a fellow who used to run the Pima College mineral class used to stop by our store, that is another story, but they had gone collecting and got a bunch of this stuff and gave us a nice piece.
The next piece is a stone from the mountains just to our West. We used to have access to one canyon that is actually visible from our place but someone locked the gate now. I went up there often when we first started here to get flat rock for a big area I used the stones as “paving” stones. Many had these banded patterns and those were the favorites to pick up.
The last one is from Sedona, the sandstone there had wonderful banding and I have better ones too but this photo was fairly easy to find. The patterns in the sandstone were iron also.
The Gila Monster
Today I saw our area Gila Monster on my late afternoon dog walk. I went back to get my camera and got some nice photos. Thought you would enjoy seeing it, my favorite lizard. This one seems to show itself every 4 years. We first saw it in 2011 then again in 2015 and now this year. You are welcome to post those photos or for that matter, any we send you.
Rockhounds should look for anything special, not necessarily what they first start out searching for. An intense gold interest may blind a person to something common yet wonderful, right under their feet. Sedimentary rocks and their related formations are a good example.
Erik Christiansen and Kenneth Hamblin say that a rock formation is, “A distinctive body of rock that serves as a convenient unit for study and mapping.” The USGS goes a bit further, writing that, “A rock formation is a body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it.” Sedimentary rocks are usually named for the formation they were found in. There are hundreds of sedimentary based formations.
To serve as an example of a sedimentary rock and its related formation for my book, I bought the treated sandstone you see pictured below. It’s about three inches by five. It shows what can be done with a common rock, transforming it into something that rivals fine wood grain in its beauty. Being sandstone, it was assuredly easy to slab it with a rock saw into a square.
The seller’s description reads as follows:
“This is natural sandstone that formed 180 to 220 million years ago by wind and water as part of the geological formation ‘Shinarump.’ The colors and design were induced by a mineral spring containing iron oxides. If you like the unusual and beautiful works of nature, you will enjoy this picture sandstone product. Truly ‘Nature’s most beautiful painting.’ This piece comes from northern Arizona. The design and patterns are natural, its color is achieved by heat treating the stone. This caused the iron oxides found naturally in the stone to react, the richer the iron the deeper the color.”
Wikipedia has this good introduction to the Shinarump conglomerate, which is found throughout the Colorado plateau. You can read it by clicking here.
