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Again Along the Spanish Trail

Important note from RC. The limestone comes first, not the calcite. In the post I have the process reversed.

Saturday, September 14, 2023

Picked up an odd rock today along the Old Spanish Trail, not far from the Junction of Highway 160. in Clark County, Nevada. What Macrostrat.org calls young fan alluvium. Lots of limestone and sandstone bits and pieces. Didn’t see anything like this rock. It has notable pockets around the rock and then lines of heavily marked material evenly radiating out from them.

There is chunk of what may be limestone at the bottom of each pocket. It reacts little to acid but I think I see some activity. The white material, less that 2 on the Mohs scale doesn’t react because it is so porous the acid soaks it up before doing anything! The white material fluoresces a strong orange/red while the pockmarked lines, full of circle and bubble shapes, does not do anything under UV.

It strikes me somewhat as being like the calcite material which I saw recently at the Kokoweef Cavern Mine complex. There are a few dead springs in the surrounding area, I am wondering if this has something to do with being formed or acted on by a spring. But I don’t know why these lines would radiate from those pockets. Or why there would be pockets in the first place.

September 16, 2023

I’ve been thinking this over by myself. No one on Mindat.org of FB has made any suggestions as to what formed the rock, other than it might be gypsum. Which it is not, much too soft for gypsum. I have a reference specimen of rock gypsum, unweathered, and a self-collected piece, weathered, from Shark Tooth Hill in Kern County, California. Both those rocks are chalky and too soft to compare with the mystery rock.

Here is my working theory. The white material is calcite, a mass of which formed around several limestone rocks. At some point the mass became tumbled and rounded in the small desert wash or channel that I collected it from. Being very absorbent, the round mass picked up rainwater which would contain carbon dioxide. A weak carbonic acid would develop when the limestone reacted to that. The limestone is now eating away at the calcite, dissolving the material over the centuries.

The pockets you see are all centered on where a piece of limestone is located. The residue seen in the lines is the acidic precipitate left by this slow destructive process. Thus, that residue or the limestone does not respond to UV, being limestone and limestone related, while the calcite (the white mass or host) responds to UV as most calcite does.


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Under SW UV. Forgive the “blue bleed”, a common sight when photographing glowing rocks.


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R.C. has just checked in. “If it’s calcite, no surprise. Rainwater dissolves limestone, which is calcite. Limestone typically has fractures which gradually get enlarged as rain water makes its way through. This is how cave systems form. The calcium carbonate (calcite) dissolved in the rainwater is what forms stalactites and stalagmites in caves, and it commonly fills in fractures between blocks of limestone.”

So, do we have a rock that was once a fractured piece of limestone, now with calcite accreting around the remaining pieces? In other words, this may not have been a mass of calcite to begin with, rather it was a block of limestone that started this all off. And then it transformed into what is seen today. Hmm. Still pondering.
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Kokoweef material self-collected on mine dumps by permission. Limestone rock on top and “popcorn calcite” underneath, the calcite carbonate deposited in the form you see here. It is unknown whether this rock came from the cavern roof, its floor, or a wall.

This popcorn calcite responds weakly under SW, producing an uninteresting cream color. It does have a short but notable phosphorescence or afterglow.


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Hawaii In A Bottle

Self collecting is great but most of us can’t go around the world to chase specimens or go back in time to get them. Case in point is this old stock Hawaiian sand from Geological Specimen Supply, mentioned in my last post.

This sand is over twenty years old, predating the ban on removing sand from the Islands.  This specimen comes with great labeling, a summary of the fuller descriptions RC provides on his site. Did you know that Waikiki’s beaches actually came from Long Beach, California? Read on and then take a look at what I am seeing under my scope.

“Sand is derived from whatever material is locally available. Beaches are uncommon on the seacliff-ringed Island of Hawaii. Occasional small coves have sand derived primarily from basalt unless there is a coral reef offshore. This sand was collected from a small cove near South Point, Hawaii, where a local concentration of cobbles of basalt and coral was the source material for this sand. The sand is primarily coral and basalt, giving it a salt and pepper look, with occasional small shell fragments adding variety to the mix.”

“Hawaii’s white sand beaches at Waikiki were initially an import, from California. In the 1920s and 1930s sand was barged from Long Beach, though the import of California sand was abandoned in the 1970s and the beach is now maintained with locally dredges sand composed of coral and shell fragments. A locally famous black sand beach occupies a cove southwest of Hilo, where the sand is entirely basalt. At Mahana Bay, near South Point, the greenish sand is composed of grains of olivine that weather out of the basalt.”

“Set of five tubes, 16 ml each, optically clear polystyrene with screw caps. The plastic tubes are practical in a classroom and are somewhat student resistant, though a cap can be unscrewed. Good for student examination. When this sand is gone, it’s gone. A recent law prohibits removal of sand from Hawaii’s beaches.”


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The focus of our attention.

Here are images just taken under my microscope. These are single focus shots, so the foreground and background focus aren’t the same. Really good photographers take a number of shots at different focal points and then have software combine them to produce a perfectly focused imaged. I’m trying to learn to do that.


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White material is probably coral, dark material basalt, and the green is olivine or peridot. Shell fragments, too. Olivine is thrown out from deep within the earth during volcanic eruptions, mixed up with basalt at the same time. Basalt pieces can make up a black sand beach, the lighter peridot may weather out of the basalt and collect together, producing a rare green sand beach.


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Closeup of a peridot or olivine grain, exhibiting poor conchoidal fracturing.


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A shell, sharpened in Photoshop.


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Unsharpened and from a different angle. Any difference?


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Another shell, this one red.


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Basalt with olivine from the San Carlos Apache Reservation in Arizona. This is what tribal member Stevie Joey mines on his peridot claims. His site is Peridot Dreams and you can learn all about gem grade peridot there. He is receptive to inquiries about touring his claim.


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Specimen tube. Buy several to trade.

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On Cats and Collecting

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A single cat always accompanies professional geologist RC on his travels and collecting. It ranges free while he works. I’ve bought dozens of well labeled teaching specimens from him in building my reference collection. On my own initiative, I’ve removed locality names.

RC with Geological Specimen Supply

T Cat goes out in the field. The Sparkletts box under him is a composite. I get egg boxes from the market, cut them horizontally in two, jam the top half down over the bottom half and glue them together, so double-walled but half as high. Eight inches high, one foot square. Then, to keep the flaps down, I get Sparkletts water boxes and cut them in two horizontally as well, but glue the top flaps to a piece of cardboard inside, making a solid top. These are a hair bigger than the egg boxes but not as tall. Half of one works as a lid, pushed down over the egg box. There’s one of these under T Cat. Each one is filled with strips of The Wall Street Journal, though any fish wrap will work. The Journal comes every day in the mail, Monday’s paper on Monday.

Every piece of rock gets wrapped up. The paper gets reused. These boxes are strong, will hold about 50 student specimens, and two will fit on my pack frame. Depending on what’s in them, I may or may not be able to get up!

The Idaho Spuds Box is full of giant oyster fossils, about a foot long. Still not unpacked! I didn’t take enough field boxes on that trip.

T Cat comes to a bell, so when I’m ready to leave, he’s in the van. He was waiting for me to finish packing. T stands for Tyrannosaurus. He was the biggest of the bunch, twice as big as the smallest. Born in a basket beside me Memorial Day last year.

I have a 7 pound and a 10 pound sledge in the van, a pick, shovel (more for roads than for rocks) a couple of Estwing geologists’ hand sledges and a couple of Estwing 12 ounce rock hammers. These have chisel heads and are easy to trim with. Estwing stopped making them, but now make a brick layer’s hammer that’s the same.

I don’t want to have to lug rocks very far for those I sell. I can tie a couple of field boxes onto a pack frame, but I want whatever I’m collecting to be close to the van.

Different story when I’m looking for something for my collection, since weight isn’t going to be much. A couple of hours of hiking results in the the best exposure of Ordovician brachiopods in the Great Basin. A couple of hours hiking gets you to the fossils. One year I was up there with a geologist friend and a student. After a long day with our noses in a shale talus slope, picking out pencil eraser sized brachs, we had hiked about half way back when my student said he had forgotten the rock hammer back at the rock pile. I had five, and I sure wasn’t going to hike back for one, all uphill!

One hammer wasn’t a big loss.

The next year I went back. Going up the talus on hands and knees, I put my hand on the missing hammer. Rusty, but it wore off. I’ve lost hammers, but that’s the first time I found one. Only time.

I don’t like the west side of the Sierra Nevada. Too much vegetation, so it’s hard to see the rocks. And then, poison oak, ugh. When I can collect in roadcuts, I do. Phyllite and serpentine, both from roadcuts in the American River Canyon near Auburn. In the coast ranges, I get graywacke from a roadcut. The rocks are more likely to be fresh where a road was cut through. Hopefully a road without much traffic!

Some rocks have to be collected from a dry stream channel to be unweathered. Tumbling down the stream removes the weathered stuff. I find the white anorthosite in the river bed of the Santa Clara River. Took me forever to find a way to drive down into it, but eventually did. In all of the roadcuts I looked at, it was weathered all the way to China, and besides, in the San Gabriel Mountains, you have to buy a pass to even park at the side of the road, so I stay away.

https://geologicalspecimensupply.com/

T-cat is indeed an orange tabby. He rode down with me to Ridgecrest tonight, and took up the same position on the boxes, though leaning on my shoulder. Helped me with a Jumbo Jack at Ridgecrest.

His mom was a tabby, became a meal for a coyote, unfortunately. She had already used up eight lives, out collecting with me near Lompoc, ran across the road to the van at just the wrong moment. Going full tilt, she hit the outside of the front tire of a speeding car, was slammed to the road and then bounced into the air, screaming. Landed, writhing, on the pavement. I thought that was the end of her, but I could see nothing broken and not a drop of blood, only a pink ear. Tail was still attached. I gently picked her up and put her in the van. She tried to climb onto the back seat but needed a hand up. Spent the rest of the day on a pillow, was better the next day, and came back to life the day after. Lucky. One second faster and she would have been under that tire, and flat. After that, she had a low reserve of extra lives, I would say. Went out one evening and disappeared. Coyotes ate two of neighbor’s daughter’s cats also, so he shot two coyotes and they have stayed away, recently.

Brother, Ralph, dark tabby, eats anything and everything. Brought in a rabbit this morning and thought it was ok to eat it on a Navajo rug. Caught that in time, so he had his snack on a towel and didn’t complain about the move. Ate all but the back legs, started with the head and ate all of it, amazingly, leaving nothing. Rabbit was half his size. Second time he’s done this, and he has made some plants in the yard grateful, as the rabbits have lost interest in them. Sister, Cucumber, snacked on the back legs. A calico tabby - tabby markings but with some orange in her fur. Cool as a cucumber riding in the van, sits on the back of my seat with her front legs over my shoulder and looks out the front window, purring in my ear. Here she is at the Gold Nugget Mine, east of Quartzsite, where I was collecting milky quartz. Not as easy to keep track of when she’s out running around, she comes to the bell. All three do, actually. When T-Cat is out exploring, he really stands out.

Cats are smarter than dogs. All Pavlov could do was to get his dogs to drool when they heard a bell. These cats come to the bell and jump in the van when they hear it, if I’m outside. Their reward is a tube of Churu.

RC

https://geologicalspecimensupply.com/
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T-Cat in the field


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Cucumber at a mine

https://geologicalspecimensupply.com/

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Rattlesnakes!

Rattlesnake fear should not stop desert wandering. They are a risk but so is a flat tire, a dead battery, or a water bladder that leaked and left you thirsty. “Those things won’t kill you!,” you might say. Well, actually, those things can. From what I read, an otherwise healthy person will face a terrible night of sickness from an untreated rattlesnake bite but nothing close to death.

Do what you can to minimize the risk. Don’t put your hands down any hole or cavity that you can’t see into. All sorts of biting creatures may be there, as well as underneath rocks. Rock piles are a favorite hiding places for snakes as their cavities and voids give them shelter. It’s really impossible to spot a rattler while walking along, they are too well camouflaged to be spotted ahead of time. Most often they will rattle at you if you pass too close, which may be only a foot or two away.

My first rattlesnake encounter was while prospecting in El Dorado County in the Central Foothills of California. I heard a strange sound from out of nowhere, something I hadn’t heard before. I looked at the ground and there was a large rattlesnake, coiled, head back, seemingly ready to strike. Maybe. Or maybe just telling me not to step on it. Anyway, I jumped back about three feet in the air, instantly enough distance to avoid getting bit. I walked off. What I noticed most was how different that rattling sound was from something in the movies or on film. Learn to listen for anything unusual and sudden in the desert, sound may be your best key. I’ve also had encounters with silent rattlesnakes, noticing them just before I put my foot down on them. That time was on a rock pile, again, beware of hounding that kind of ground. In my experience, rattlers can be moving around anytime of day.

Above all, DO NOT SHOOT A RATTLESNAKE! Just move away. You’re far more likely to shoot yourself and this kind of accident occurs throughout the West on a regular basis. Just move away.

On Mount Diablo in the Bay Area I was at a trailhead parking lot when a woman ran up to me, completely out of breath. She asked if there was a ranger around and I said no but that I could try to help her find one. “What was the problem?” She said her hiking group was stopped on a trail with a large rattlesnake in front of them. I didn’t understand what she was getting at. And then, taking a guess, I said, “Have the group walk around it. Give it a wide berth.” She kept staring at me, obviously wanting another answer. I then said, “It will not follow you or chase you down.” Her whole face lit up with happiness and she went off running from where she came. No, they will not follow you.

Some people have the background and interest to move snakes by hand but this is the sort of thing that requires training and knowledge. My friend and mineral dealer Rolf has many rattlesnakes on his southern Arizona property and he has learned to deal with them, even the deadliest. He does not shoot them!

This is a story with pictures that he sent me this morning.

Hi Tom,

Yesterday we had an interesting thing happen. After the big rain Saturday, Sunday was much calmer and no rain. Yesterday afternoon Mary drove to town to pick up a few things for dinner.

Before she came back I was going to go over and turn off the air conditioning in the store since it was on for about two hours and we keep in off after about two hours on so as not to use too much juice.
I was about to let the dogs out but thought Mary was about to come back and they could get in the way when she parked since Shadow “don’t know nothin about cars” yet, so I decided to leave them in.

I was walking down our ramp and didn’t get far before I saw the rattlesnake. It was right where the dogs often run. It was crawling in the open. I went over to see since it looked different. Sure enough, it was a Mohave Green Rattlesnake, which in the 38 years we have been on the place we have never seen. The Mohave Green is the most dangerous rattlesnake because of its temperament and its much worse poison. They are one of the most toxic snakes in the world. Our bio-habitat is not quite right for them but here it was.

I put it in a bucket and was surprised it was not any more aggressive than the diamondbacks we always find. Since I know if its toxic nature I wanted to document we had found it but not put it out again to get a natural background so got a piece of glass and just finished cleaning it when Mary got back. I put the glass on the bucket instead the lid and got the camera.

The snake was a beautiful snake, if you like that kind of thing, and had coiled up but kept rattling. I took some photos and then replaced the lid and put a piece of railroad rail we use for a door stop on top of the lid, you know just in case kind of thing. We certainly don’t want that one on the place. I was going to take it off with the ATV to where I often release snakes but Mary said she had a better idea. First it was about 15 miles away and a much better habitat for this species.

We drove to the place and found a good release spot and it was still only about 5:30pm so not too hot anymore and a good oportunity to get a couple of photos.

I did just that and thought I attach the three best photos so you can see the snake.

Fortunately my snake eye is still quite sharp and my working with them is like riding a bicycle, you don’t forget all the years of doing it.

Great animal and I have a big respect for them but not on our property.
Mary thought since it was so plump it could have been ready to give birth and that would certainly have been bad. So, off it went and we were again talking on the drive home how pretty that snake is and just how dangerous.

Otherwise not much happening here.

Hope things are good your way.

Later,
Rolf


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Sandstone Collecting and A Gila Monster

Sandstone Stuff

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.

Have a great day.

Rolf

Rolf and his wife Mary run Sunshine Gallery and Gifts in St. David, Arizona. It is a destination rock and mineral shop.

Another angle

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