Qualitative EDS analysis on The Mystery Slab

In General

In my book I discuss different kinds of tests. I won’t explain anything about testing here; this is simply a page for fluorescent mineral collectors and other mineral enthusiasts to drawn their own conclusions.

Kerry Day is well known on Mindat and has been performing qualitative testing for over twenty years. His website is http://kaygeedeeminerals.com/ and he is on Etsy.

He has tested materials for me before and I have bought some fine specimens from him. He is, as we Americans might say, a good egg.


This is a slab of unknown origin bought for five dollars at a rock shop in Kanab, Utah. It is 2.5 in hardness and does not fizz under 10% HCI, although it does produce inactive bubbles. It is about five inches in length. It breaks apart easily and has no sandstone like texture, more resembling hardened clay than anything else. But obviously hard enough and structurally sound to be slabbed.

Visible light

Shortwave UV 18 watt Way too Cool Lamp

What The Following Numbers Refer To

#1 red mineral: The darkest material in visible light, with a faint reddish appearance. This material fluoresces red under SW UV.

#2 green mineral: The light green material in visible light. This material does not fluoresce.

#3 Grey: Colorless or mostly so material forming what I am presuming to be the matrix of the rock. Does not fluoresce.

Aug 22, 2019

Hello Thomas:

Here are your latest:

The following spectrum was created with a Cambridge S100 SEM, a XR-100-CR pin diode detector and DTSA software. X-ray counts are on the vertical axis and X-ray voltage is on the horizontal axis. For various reasons peak heights are not directly comparable.

The accelerating voltage was 25 KeV. This setting exaggerates the higher voltage peaks. Detector efficiency peaks at Ca, thus, all Ca peaks are greatly exaggerated. NA IS VERY POORLY DETECTED BY MY HARDWARE.

Some elements create more than one peak. All elements have been labeled.

My X-ray detector cannot detect Li, Be, B, C, O, N or F.

Uncoated specimens charge up under the beam and generate false peaks such as Al (1.49), Si (1.74), Cl (2.61) and Ni (7.47). These elements are coming from the inside of my SEM chamber. Surrounding minerals also
contribute. Any element I believe to be extraneous I did not label.

#1 red mineral = I suspect Smectite Group – Sauconite. There are localities in both Colorado and Arizona.

#2 green mineral = Malachite in Ca matrix.

#3 Grey = If it didn’t fizz I would guess Fluorite.

The Kokoweef Cavern/Mine Complex

A fee dig today with the Southern Nevada Gem and Mineral Club to the Kokoweef Cavern Mine in the Mojave Desert.

Just a few photos now, more later. Much to write on. Travertine, onyx, and wonderful calcite cave popcorn, a stalactite which shows outstanding cleavage. eBay has specimens like the one pictured below made into cabs. Again, more later.

Members examining what to look for. The operator is donating this material to a school program.


A closer look at the material.

The tailing pile is steep and rocky but provides outstanding examples of this bubbly looking stalactite formation, much still clinging to its limestone host.

Some popcorn from the front.

And the same piece from the back, possibly cleaved when the cavern roof fell.

Well established buildings out of view, the result of former commercial zinc mining. This is not public land. This is private property as the result of a once patented mining claim.

The road in. Desert driving. At one fork a sign points to the right for the Kokoweef. Instead, one goes left.

Steven Bisyak documents everything about the area’s history and will gladly discuss same. I am trying to find a magazine article he referred to, “Uncharted Caverns of The Desert by Phillip Johnston.”

Steven Bisyak explaining the history of the cavern and the mine and his attempt to document its history.

Nice UV reaction on calcite under shortwave. The darker rock is limestone.

Visible light of same rock.

Faced with a bad stretch of road, a Jeep owner admitted to me that he didn’t have skid plates. This was my reaction.


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Moving On in a Desert Wash

While my book lies dead or dying, I continue to collect and learn. The world is too fascinating to continue mourning.

On Friday I collected from two desert washes near the colorful art installation called Seven Magic Mountains outside of Las Vegas.

This first photo shows mud cracks in stone. Slate or some such. Does not fizz readily under acid like the next rock.

This second photo is a poor example of limestone with a surface solution, collected that Friday just for illustration. Notice how much finer the lines are than the mud cracks, a closer knit group of spider webbing. Limestone with a surface solution is common throughout the Southwest. Keeps scrolling to see a reference specimen.

This third photo is a reference specimen of limestone with a surface solution. I bought it from professional geologist and former instructor R.C. de Mordaigle. He runs Geological Specimen Supply in Olancha, California. It’s the best place to start your reference collection of common and uncommon rocks. R.C. was a great supporter of my book.

R.C. explains these cracks in limestone this way, “In arid areas both limestone and dolomite develop a rough dissolved surface from the action of weak carbonic acid as atmospheric water picks up carbon dioxide . . . .”

What the collector really wants to find in wash are ripple marks, distinct marks in stone caused by wave action millions of years ago. This specimen is mudstone from somewhere outside Barstow, California. Look closely at the second photo. This isn’t just a piece of somewhat striped sandstone. Notice how it has real relief. Ripple marks.

Notice the relief in this second view.

I was on a Barstow area field trip one summer and saw a woman collect a nice ripple mark specimen from a desert wash. That arroyo had just been hit by a summer rain. Alas, I myself did not find a ripple mark but I did collect a nice piece of sandstone with dendrite markings. Another story for another day. Keep looking!


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An Apology Regarding My Book

As a professional writer I am embarrassed to write this. I do not give excuses about my work. I communicate and cooperate with my editors, I beat word count, and I always meet my deadlines. Always. I keep my word.


Due to circumstances beyond my control, the release date for my book is now September, 2020. I apologize to everyone to whom I promised a release date of early 2020.

In the upcoming months, please send me any updates on your mine, claim, business, or activity. I’ll incorporate these changes into upcoming revisions with my editor.

Again, I apologize for this major change that was only revealed to me today, weeks after I submitted my MS before deadline and under word count.

I could not have anticipated this and I regret that the good publicity that could have come to you sooner will now be more than a year away.


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Mineral Mystery Musings by Rolf Luetcke

Hi Tom,

There are things out there that certainly are mysteries. I have quite a few in my past that were interesting.

One was a fellow on Mindat.org who found me by way of that site. He was from Tucson and messaged me about something he found deep in the mountains of SE Arizona. He was not a mineral guy but found a vein of quartz that had a silver material all over it and he was convinced it was a new metallic deposit he had discovered while bird watching. He sent me a piece and as soon as I saw it I knew it was not a natural material. I emailed him back and said I thought it was something man made. He just couldn’t believe it since it was “in the middle of nowhere” as he said. I told him to take it to the University of Arizona Mineral Museum. I told him I thought it was some kind of stuff painted on the rocks since it was only on the outside and didn’t go into the quartz where he broke it.

He took it to the University and they were also intrigued and said they would test it. He wrote me back a week later and said he got the results and it was aluminum paint. He was certain he had found a new mineral deposit but someone had actually painted some rocks in the middle of nowhere.

Another one was a fellow we met at the shop had been in the same area of old mines and he was a mineral collector, although not a very knowledgeable one. He posted on Mindat that he thought he found Millerite in the Patagonia area. He had not contacted me until after he had posted the material. I told him that was not possible because there was no chemistry in S Arizona to support that. Another friend had been with him and he gave me a piece of the same ore and as soon as I looked under the microscope I saw it was Stibnite, a mineral that was supported by the chemistry. They did find that Stibnite in an area Mindat did not list for that mineral’s locality, so that information has been added to Mindat. It was not the Millerite he hoped it was.

Dreams die hard. Mary told me many years ago when I found a new thing at a local mine and thought it might be some rare species, she said it is probably a much more common species but in a form I had not seen. She is usually right in pretty much all these cases and I learned a valuable lesson. I passed that onto the friend who gave me the Stibnite and he now thinks that his material was probably a more common mineral.

Got a bunch of those stories over nearly 48 years of mineral collecting.  Having worked with minerals now for so long I have gotten pretty good at identification but I do need to use a microscope to be sure.

Will be interesting to figure out what that “weird stuff” turns out to be you found in that field. Seems rock related and not necessarily mineral related and that is often harder to get figured out than a mineral.

Have a great day.


NB: Rolf is a longtime mineral collector and rock shop owner in Southern Nevada. Read about his must stop shop here.

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It’s All About The Gram

An upcoming road trip will take me to Boron, California to stop in at Desert Treasures, if they are open. On the outskirts of Boron, the Rio Tinto Borax Mine Visitor Center is next and then on to Barstow to visit the Desert Discovery Center to view The Old Woman Meteorite. Then over the Tehacapi Pass to Bakersfield.

Next day to Shark Tooth Hill and The Ernst Quarries, next to Randsburg, and then on to Ridgecrest to visit Minerals Unlimited.

North after that to Death Valley, then east to Beatty, and then a drop back down to Las Vegas. I will be posting photos along the way if I have cell coverage.

If you are not on Instagram, consider joining. It’s all about the gram.

My username is: @tgfarley

On the web: https://www.instagram.com/tgfarley/

My Apologies to the BLM

I wrote previously that the BLM doesn’t recognize rockhounding anymore as an activity. While that may be the case at the national level, the BLM in California still recognizes rockhounding as the vital and rewarding hobby that it is.

This page recognizes rockhounding with a video featuring Bill Depue, Founder and President of Diamond Pacific Tool in Barstow, perhaps the leading manufacturer  of lapidary equipment in the world. I had the great privilege of meeting Bill a month or two ago and I wrote about it here. In keeping with his modest character, Bill wears a Diamond Pacific hat but never mentions his involvement.

Interestingly, that page does not list all California BLM  rockhounding sites, it just mentions that the activity exists. Their Needles field office once had no reservation about describing sites.

Click here for an archived page that list sites under Needles’ management along with photographs showing what might be collected at each one. This is true endorsement. But I appreciate any effort that BLM California makes. Thank you!

Photograph below of Bill Depue.





What Rock, Gem and Mineral Photographs Can’t Show You

A static photograph can’t adequately show sparkles, often the most joyous character of a rock, gem, or mineral.

Here’s a static photo of rose muscovite, an absolute star in the sun:


We see poorly defined points of light but not sparkles. Perhaps a hint of sheen. If this rock is put into absolutely perfect focus those spots will disappear completely.

Contrast this to a dynamic portrayal of the same rock. Watch the video all the way through.

Amazing difference, eh?

When looking at a photograph of a rock, gem, and mineral, you may not be getting the whole picture. When out in the field, even in country full of volcanic material, watch for sparkles. Some of those rocks shine. Just not in pictures.

Print Out a Map, if Not for You, For Someone Else

On Sunday I drove a little bit of the Lake Mead Recreation Area, aided in part by a map created by Jim Boone, the producer of BirdandHike.com. His site is the ultimate resource for exploring the natural world around Las Vegas, Clark County, and Southern Nevada.

Although it is a non-collecting area, I was there to take a mental health break and to bring back photographs of different volcanic features.

As I made my way back to Highway 93 on the Kingman Wash Access Road, I was stopped by a couple driving a low slung Subaru. The driver asked, in an excited and somewhat nervous sounding voice, “Do you know where this road goes? Are you from around here?” Hmm, I thought, traveling off-pavement with no map and no idea about what lies ahead. Not my style but certainly adventurous.

I handed him the map I printed out from Jim’s site. The driver grabbed it eagerly, clutching it with both hands. The couple stared at it intensely while I described the main road as fairly decent but not the side roads, which could turn into Jeep trails. They nodded and continued to look at the map. Jim had outlined the area, not in fantastic detail, but enough to get one in and out and to show some points of interests. Just right.

As they continued staring, I asked if I had written anything on the map. They turned it over and said no. I said, “Keep it, I know my way out.” They were very pleased with that and had big smiles on their faces as they drove off into the previously unknown wilderness.

This reminded me of hikers I have encountered who have run out of water and have eagerly welcomed a refill. We’re all out there together and we need to watch out for each other.

In my truck are three different navigation devices and four to communicate with. Certainly not everyone should be expected to carry all that equipment. But it is equally certain that we should be ready to share the wealth with any decent person who needs it. Now that I think about it, when you print out a map, make two copies!