Afterglow demonstration from the Princess Pat Mine collecting area in San Bernardino County, California. This characteristic is extremely difficult to capture on video. In person the effect lasts for nearly a minute. I’ve run the video at half speed at a certain point to simulate what this looks like. The text announcing this point goes by quickly.
This is short wave under an 18 watt Way Too Cool Lamp. The mineral is willemite, the parent rock undetermined at this time.
November 12, 2019 update: If you look at this video on a big screen TV (Search YouTube for “Thomas Farley Channel” you’ll see the afterglow much better represented. I cut the video off during editing at the point my computer monitor showed no more glow. On a big screen, the glow still has a way to go. I will reshoot and you can then see the results on a TV.
That website is difficult to use. My iMac has a native calibration setup process that does not push the length.
In full screen mode using the original HD file, the last spot I see on my iMac is at 25 seconds. Even though I shot this in HD, 3840 x 2160, compression is going on at Vimeo where I uploaded it originally and then published it through Vimeo to YouTube. And I scaled it to 1920*1080 before uploading.
The Princess Pat Mine collecting site is described at this website by Justin Zzyzx who who has written Rockhound Barstow, the best and most current field guide to California’s Mojave.
Located now in Golden Valley, The Gold Lady is a great prospecting and metal detecting store. The Gold Lady knows her stuff and she is an unstoppable when it comes to her own detecting; she is constantly in the field and mightily protests when health prevents her from going out.
The old store was fine but this new location promises good things. The Gold Lady has been advocating the Minelab Gold Monster 1000 for some time. Although I only saw it work at her old shop, its operation looks simple with a fairly flat learning curve. It looks like a great choice for the beginning prospector. Prospecting supplies and perhaps local maps.
The Gold Lady
52 Hope Road, Suite 2
Golden Valley, AZ 86413 (Northwest of Kingman)
Simple look at basic screens or classifiers. Uniform material makes for the best panning. Deciding how far down to screen depends on your patience and the size of the gold you are recovering. Probably small. I’ll try to put together a video that shows wet classifying, running coarse material down to fine.
In this video you’ll see regular screens and deep ones. Deep ones allow you to overfill a five gallon bucket just enough to work your material wet. They’re not meant to process more material, you really only want a screen a third full at the most when classifying.
Yesterday I went out to Lathrop Wells in Nye County looking for placer gold in featureless alluvium, possibly 240 deep where I was. I had the audio on my metal detector turned way down to save on battery life. I wasn’t listening for gold nuggets or gold in quartz that day, instead, I was reading the display on my Whites’ black sand tracker feature. It gives a numerical reading on any ground the coil is moving over. I sample when I see it go above 45, unfortunately, it only hit 42 once.
But one sandstone rock with black streaks blasted out despite the volume on the speaker being turned down. Well, I thought, that’s interesting. Aside from the possibility of gold, I wasn’t aware of any other metallic ore in this ocean of alluvium. No mining district here or any past mining activity. The signal sounded like the hot rocks I encountered everywhere in the the canyons of the forks of the American River. You get what sounds like a good signal and then you listen as the GMT cancels the signal out. I should explain.
A decent gold signal is a strong, low, mellow tone that happens each time the search coil passes over a rock. The signal remains no matter how many times the search coil goes over the target. What usually happens with a bad rock, often with an iron component, is that a signal is heard initially but that signal disappears after several passes. With each sweep the GMT is logging information to determine if a rock is ferrous or not. If so, the signal weakens and then goes away. This is called cancelling out. This rock did not cancel out. That’s what you look for with gold. Most non-metallic rocks are neutral and the GMT also passes them by without raising any signal.
The signal, however, was weak and wavy. Not good. You want to hear a steady signal, nice and low. You’ll rarely hear this. The Whites also has a probability of iron meter. It was reading at nearly 100%. Okay, I thought, this is coming home with me to figure out later. When I broke it open at home it revealed a dark material like that which it showed from the outside, hardness about three. Not attracted to a magnet, not even my super magnet. No U, no UV. Dull, off-white streak on a black streak plate. Metallic luster when freshly broken, annealed appearance in some spots with fresh breaks. Crushed and panned a piece, nothing unusual, no free gold at the macro or micro level.
To get the ID process going I mailed off a chip today by regular US mail to Kerry Day. He charges less than ten dollars for a seasoned opinion based his experience and the results produced by his electron scanning microscope and its supporting software. I’ve written about his service many times before. I taped a small chip to my business card, put it in a normal envelope and the charge for mailing was less than $2.50. Make sure your sample fits into a No 10 first class envelope, anything bigger might be considered a package and then mailing rates go up enormously.
My Falcon MD-20 handheld metal detector indicated that the material was non-ferrous, despite what my Whites said. Ferrous material produces a noise when an object goes away from the Falcon’s probe. Non-ferrous produces a signal as you move material toward the probe. This material only produced a signal going toward the probe, however, there are cases where a material is so strong that it may overwhelm the device and make it impossible to determine which is which. There were also some tiny gold colored spots arranged in lines here and there in the black material. On seeing gold coloring, always assume mica or pyrite. The nice thing about the Falcon handheld and the GMT is they do not react to pyrite. Never. I have lumps of pure pyrite and both devices stay silent when moved over that nonsensical material. Pyrite is an iron associate but too weakly so. Yet the rock continued sounding off. I suspect that it was is not those gold colored specks making the noise but the black material.
Unable to resolve the difference between the two metal detectors, I gathered up the rock pieces and went back to my truck and the GMT. I ran the coil over the rocks again. Sure enough, I hadn’t read the meter right in the field. This time the meter did not go above the halfway line, indicating something less than ferrous. The signal remained weak but still would not cancel out. Now, I just wanted to figure out what the material was, never mind that it wouldn’t be worth anything.
After further research I discovered that there are three long abandoned copper mines in the hills that drain to the wash I had been in. I still don’t know what that black material is but I am now convinced that I have a rock with copper. Not worth anything but a nice find. Those exploratory diggings are now unclaimed and the ground is on open BLM managed land. A little close to the Nevada Test Site boundary but at least a mile away. I may go exploring there to look for copper mineral specimens. Here’s a link to one mine listed at the the MRDS if you want to go:
Got to get out the door quick to hound some more ground. A few words here on tuff since I am investigating a tuff formation outside of Las Vegas. See previous posts.
Tuff are rocks formed from solidified or lithified volcanic ash and rock fragments thrown out of a vent. They can be all colors and densities but a common feature are clasts, rock fragments within the tuff. Not all tuff contains clasts but this is very common.
UPDATE: November 11, 2019. Made a better video than the previous. Retains cat content.
I might have found an example of explosion tuff. This is where rocks settled onto the ash, rather than being embedded in it. Need to collect more of that, break some of it open, look for other things while I am out in the field, and on and on. . .
Another look at this possible explosion tuff and a still photo of what I am calling “The Shark”. A single, angular clast sticking out of tuff from the same area. Looks like basalt to me. Is this explosion tuff?
The results are in on those small crystals I found in tuff near Jean, Nevada. Kerry Day says they are a mystery mineral, possibly orthoclase. That’s a feldspar member, a group of rock building minerals. Although the geologic map for the area lists sanidine as being present, geologists aren’t all skilled mineralogists and sometimes small mistakes occur. Sanidine is another feldspar mineral, closely related to orthoclase.
Feldspar imparts a pink color to many granitic rocks. Feldspar minerals aren’t much collected unless they display good crystal form or come from a rare area. Like the anorthoclase found at the Mt. Erebus Volcano in Antartica.
Mindat.org says orthoclase is “a alkali feldspar intermediate between low sanidine and high albite.” Hmm. I’ll have to read up on that but in the meantime have asked Wendi at Minerals Unlimited to send me specimens of those two. I’ll put them under my microscope to compare them to what I have. Positively identifying any of these minerals by sight, however, is really impossible.
Minerals.net has an excellent article on anorthoclase which says that distinguishing between albite, sanidine, orthoclase, and microcline requires x- ray analysis, probably X-ray diffraction. The usual visual and physical tools for identification: determining luster, hardness, cleavage or fracture, and so on, don’t matter much when minerals are quite alike. Rather, something like the percentage of potassium in a specimen may make the difference.. And you’re not going to determine that with with a field guide or anything else online. Test.
This is a labeled spectra of the crystal sample I sent Kerry Day. His conclusion:
“Mystery mineral = Not Sanidine, insufficient K. Probably Anorthoclase. (Now orthoclase, ed.) The spectrum does not fit Chabazite.”
With that comes his qualifications:
“That 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. [NA is sodium, ed. note]
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. [the lighter elements, ed. note]
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.”
So, what do we have?
One Method For Further Testing
Calculating a mineral’s identity by its geochemical composition is a good step when the usual ID methods fail. Kerry Day uses a method called qualitative EDS analysis. A qualitative test differs from a quantitative test in that it may be less precise but it is far, far less expensive. Quantitative testing is usually only needed when publishing results in the sciences or when working in an industry with critical concerns. NASA needs quantitative, you probably don’t.
Kerry Day uses his own Scanning Electron Microscope or SEM to perform mineral identification. He writes, “When high energy electrons from a scanning Electron Microscope (SEM) bombard a mineral grain, they generate X-rays of voltages specific to the atoms being bombarded. An Energy Dispersive Spectrometer (EDS) then detects these X-rays and displays them in graph form on a computer. Interpretation of the raw graph is called Qualitative EDS analysis.”
An element-based formula can express a mineral’s chemical makeup. Like this for turquoise:
CuAl₆(PO₄)₄(OH)₈ • 4H₂O
Cu is copper, Al is aluminum, PO4 is phosphate, OH is hydroxide, and H2O is water. The subscript values indicate their proportions.
Day considers the elements reported in a sample. Relying on years of experience, he then tries to match these elements to a mineral formula. His equipment does not test for every element nor do other kinds of analytical tests but the major elements present are often enough to identify a mineral in this manner.
Day charges $8.00 for each spectrum conducted, with the peaks of the spectra indicating which element is present and the height of the peak roughly approximating its proportional abundance. His report generates a labeled-spectra which is e-mailed and which you can see above. Kerry says, “A sand-sized grain or a scraping in a gelatin capsule or taped to paper is sufficient for the this analysis.”
You might pay more for postage than the test itself if you send your material as a package. Fit your sample instead into a No. 10 envelope. The USPS should charge less than $2.50 for a first class envelope to Canada. Although Day accepts cash tucked into a sample’s envelope, you can pay for testing through his Etsy store. That will prevent customs or your shipping company from delaying your sample should they have a problem transporting money.
His selection of minerals and rocks, by the way, is wonderful. Inquire if you don’t see something you are searching for. I have bought many things from him. Back to testing.
This testing is primarily for minerals, not elements. For example, an EDS analysis of colored chips from a petrified wood sample will probably reveal the mineral quartz, the host mineral, and not the trace elements coloring the chips. In the case of pet wood, Bob Jones says these colors could come from vanadium, chromium, manganese, iron, cobalt, and many more. Any of the so-called transition metals. Again, these are elements, not minerals and Day’s equipment may not pick them up. An EDS analysis may disappoint when a minerals are expected and instead undetectable trace elements produce an inconclusive report.
If known, you might include in your correspondence with Day the minerals documented to exist in your collecting area. Mindat.org might provide this for a well noted area or perhaps a list might be had from the applicable geologic quad.
What Now With My Mystery Crystals?
I’m wrapping up my efforts with the samples I collected. I’ve noted their location in a Word doc and have included portions of the Jean Quad, the geologic map of the area. Along with the test results Kerry Day provided. It’s not everyday that you find crystals that come in squares, rectangles, and sometime arrowhead shapes. It’s been fun. My mineral friend Rolph in St. David Arizona, says orthoclase is common there and brings about a sparkling character to many areas.
I’ll now store away my samples with this paperwork and go on to finding other things. Perhaps I’ll make this file available online in case the one or two feldspar specialists in the world ever decide they want to look up this occurrence. Maybe some student twenty years from now working on their Masters’ thesis. It could happen! 🙂
Returned to my collecting area with a rock that showed interesting character but little lime/green under SW UV. Best to break it open to see if any more UV would be revealed. While I hoped for decent response, I was not expecting this rhyolite to be a geode.
Last year I collected a similar looking rock from the Armagosa Valley in Nye County, Nevada. Bryan Smalley cut it open and it was just a sad looking mix of brown rhyolite and quartz. This is now my first self-collected geode. I normally would not hunt them since I have no idea where they might be.
I am still looking for uranium occurrences and have had yet to find any. I may, though, have identified sanidine crystals in tuff so that is a good thing. I’ll be back.
I may have also discovered a concretion naturally split apart. See below.
Concretions are typically sandstone based. Those might form around a piece of a shell (limestone in nature) or a bit of calcite. My rock fizzes hardly at all, which makes me think it is not sedimentary. Bates and Jackson say concretions can also form around a leaf, bone or fossil and that concretions can derive from “fragmental volcanic rocks.” I’m still reading up on this.
Picture below is my rock and a reference sample I have from Geological Specimen Supply. That rock comes from the Tule Wash in Imperial, County, California.
Been waiting on others for help with identification of tiny crystals found in tuff near Jean, Nevada on a recent field trip. Thought it chabazite at first through photos but that material is too soft at 4.5 to 5 on the Mohs scale. My crystals are at six.
Wendi with Minerals Unlimited sent me some chabazite but it does not match up to what I have. Tried sending a sample to Kaygeedee Minerals in Canada for testing but DHL has held up my package. Called immediately after they called and got a recording that said they were closed for the day. More waiting.
Here’s what tuff looks like in a video, although it can take on many forms. I have five reference samples. As you can tell with common tuff, weathered surfaces are deceiving. Freshly broken surfaces reveal an ash gray color.
And here are what a beat up crystal looks like. Too often mineral books want you to find a perfectly shaped crystal for identification. This is what you usually find. The clue here, though, is conchoidal fracturing, which does help with ID.
These are my mineral choices according to the text of the Jean geologic quad. It is often extremely difficult to determine what a rock or mineral is if it is outside of a mining district or away from a described mine. I had a similar experience near Plymouth, California with an outcropping of massive botryidal hematite and goethite that took nearly a year to of persistence effort and many experts to identify.
“Tb Tuff of Bridge Spring (middle Miocene, 15.2 Ma) (Faulds et al., 2002a, b) Purplish-gray to light-gray, weathering pale-brown, moderately to densely welded rhyolitic ash-flow tuff containing 10–15% anhedral to subhedral phenocrysts of sanidine and significantly lesser amounts of biotite, clinopyroxene, plagioclase, hornblende, and distinctive, honey-yellow sphene. Lithic fragments (~1%, <5 mm) of reddish and dark-gray intermediatecomposition volcanic rock and lesser granitic rock. Basal dark-gray vitrophyre commonly found at base. Weathers to rounded boulders. Distinguished from Tmd by presence of ubiquitous sphene and somewhat smaller sanidine phenocrysts. Appears to have accumulated in a northeaststriking topographic low defined by the underlying Trg. Thickness 0–25 m.”
I hope to update this post as I get more information. Just waiting on others. And the postal system and DHL.
This is a revision of my first article for Rock&Gem Magazine, who has permitted me to present it here. Since this article was published in January, 2016, Dean Otteson has passed away. He was a good man. Rest in Peace.
In 2019 the Ottesons have permitted fee digs on different claims for a few area rock clubs. I went on a recent trip with the Southern Nevada Gem and Mineral Society to the Broken Arrow claim. We hunted variscite and turquoise on the dumps. The Southern Utah Rock Club, of which I am also a member, was also allowed a fee dig in the last few months.
I Suggested Titles
III Access and Amenities
I Suggested Titles
A Turquoise Tale – A Field Trip to Dig at The Royal Royston Claim Near Tonopah, Nevada
A Turquoise Odyssey to Tonopah, Nevada – A Gold Prospector Comes to Love and Learn About the Gemstone
A Turquoise Adventure – A Field Trip to The Royston Mining District Near Tonopah, Nevada
Near the western high-water mark of the Great Basin’s Sagebrush Sea sits Tonopah, Nevada, at 5,394 feet. I came to this high desert town to search for turquoise, to experience a hunt on one of the last gem grade turquoise mines open to the public in the United States.
A friend’s interest in turquoise jewelry had ignited in me a curiosity about the semi-precious gemstone. While I am normally a gold prospector, using my metal detector to find gold in quartz, I became more and more interested in turquoise as I researched it on the web.
An upcoming trip to Las Vegas would take me through Tonopah. From my investigating I knew that the nearby Royston Mining District was famous for turquoise and that the Otteson family of Tonopah offered a tour and a dig at their Royal Royston claim. The $100 dig fee did not deter me since food, gas, books for research, and a hotel room would cost more than that. Besides, what price adventure?
Tonopah is centrally located between Reno, Nevada and Las Vegas, a day’s drive from either city. I began my turquoise odyssey in Reno, principally because I was moving things from Sacramento to Las Vegas, my soon to be new home town. The date was October 20, 2015.
To get in the spirit of things, I first visited the W.M. Keck Earth Science and Mineral Engineering Museum on the campus of the University of Nevada at Reno. The museum is in the Mackay School of Mines Building, a classical looking structure in Flemish-bond brick. I read there was an outstanding display of Nevada turquoise inside and I was not disappointed.
A large display cabinet houses the Luella Margrave turquoise collection. It has samples from around the world, including over 30 specimens from different Nevada mines and localities. Mostly rounded and polished stones, the collection includes a Blue Gem mine specimen that weighs 704 carats! The grouping also shows stones often mistaken for turquoise, such as howlite, chrysocolla, wardite, imperialite, and variscite.
“The Keck” as the staff sometimes call it, houses other fine collections. Gold and silver examples are first class and the history of the Comstock strike is well presented. Any rock hound should tour the museum’s displays of minerals, fossils, mining artifacts, and ores. Vowing to come back soon, I next drove a few miles north to visit the publication sales and information office of the Nevada Bureau of Mines and Geology.
The Bureau maintains this sales and record keeping outlet at the Great Basin Science Sample and Records Library building on Raggio Parkway in Reno. It’s recognizable immediately by its insulating gold clad windows. During my internet research on Nevada turquoise I kept coming across references to a Frank Morrissey, an inveterate amateur turquoise collector who visited nearly every turquoise mine in Nevada. At “The Bureau,” I bought a copy of Morrissey’s seminal work, Turquoise Deposits of Nevada, field checked and published by the NBMG in 1968. Although the document exists as a .pdf file on-line, I purchased the work for its foldout map and, to a degree, as a souvenir.
After some impulse buying: Geology of Nevada, a boxed NBMG rock and mineral collection, and a turquoise picture postcard, I fueled my truck and headed east on Highway 80 to Fernley, Nevada. It’s necessary to go east to hook up with I-95 South, which takes you all the way to Tonopah.
Click TWICE on a photo to see it full size.
As I negotiated the light traffic and rural intersections I kept looking at the post card I bought, slightly bent and yellowed on the back, perhaps from years of waiting to be sold. Its caption, written by the Bureau, neatly summarized what I was starting to learn: “Turquoise is a complex mixture of copper, aluminum, phosphate, and water, and is found in veins, seams, and nodules in a variety of rocks. It varies greatly in color from the highly prized shades of blue, green, and blue green to almost white or grey.”
That correlated with my notes; the United States Geological Service wrote something similar on the web. “Chemically, a hydrated phosphate of copper and aluminum, turquoise is formed by the percolation of meteoric or groundwater through aluminous rock in the presence of copper.” Water seems key. Arid climates favor turquoise. Too much water, by precipitation or otherwise, and the enabling chemicals are flushed out of a rock’s cracks and fissures, never to deposit turquoise.
Turquoise’s formula is CuAl6(PO4)4(OH)8•5H2O. Where Cu is copper, Al is aluminum, PO4 is phosphate, OH is hydroxide, and H2O is, of course, water. The differences in color and shades within a color, reflect the different concentrations of each chemical. Lesser chemicals such as iron also affect color, as does the host rock or matrix of the stone. [Interestingly, Mindat.org and Gemdat.org disagree on the formula for turquoise.]
The Lowrys, writing in Turquoise Unearthed, say that, generally speaking, “Stones with more copper appear bluer, while those with less copper and more iron are greener.” Other experts, such as Colorado College’s Richard M. Pearl, author of Turquoise, are or have been skeptical and left iron’s contribution unresolved. But as I drove on and as the country emptied, I thought less about chemicals and more about the people who first occupied these lonely lands and how they worked turquoise into their lives.
Turquoise mining and processing in Nevada goes back at least 600 years. Research Geologist Joseph V. Tingley once wrote that Anasazi (Ancestral Puebloans) mined turquoise near present day Boulder City in southern Nevada from 300 to 500 A.D. In Nye County, my eventual destination, George Schmidtlein in 1925 was led by a house servant to what she said was an old Indian mine in the Toquima Range. Fifty miles or so north-east of Tonopah, Schmidtlein found turquoise chips, crude stone tools, and a narrow 12 to 15-foot shaft. He subsequently claimed the property, calling it the Indian Blue mine.
From their center of power in what is now New Mexico, Anasazi traded turquoise for almost everything, including California seashells, copper bells, obsidian, and even macaws from Mexico. But what about this mine near Tonopah? That is Western Shoshone country. Although my research hadn’t yet finished, it seemed likely that those early people also produced finished turquoise for its ornamental, monetary, and sacred value.
Mine scarred hills and tailing piles greeted me as I drove into Tonopah. The city is built on top of countless abandoned tunnels and mine workings; a town alive on the remnants of the past. My destination was the historic and period restored 1907 Mizpah Hotel, whose management partners with the turquoise tour and dig. This arrangement benefits everyone.
The Ottesons are Royston Mining District claim owners and tour operators. They run rock saws and polishing equipment in the Mizpah’s basement as well as a retail store on the first floor. Tour participants get a dig fee discount if they stay overnight in the hotel. And all dig attendees, no matter where they stay in town, meet their guide leader at 10 in the morning in the grand lobby of the Mizpah.
After a wonderful dinner and overnight at the Mizpah, I got out at 8:00 A.M. the next day to walk around the Tonopah Historic Mining Park. The park is right in back of the hotel. Challenging trails lead to a myriad of mining features: hoist houses, a powder magazine, a tunnel, and viewing areas for many now closed silver and gold mines. For the less physically inclined, the Visitor Center offers easy access and plenty of parking. The rock and mineral displays there offer a great look at Nevada’s geological resources. It was here that I saw my first turquoise rough and I found that sight compelling.
Previously, I had always seen turquoise set in jewelry or as polished stones. The rough, by comparison, had a raw and natural look that I liked very much. Royston District turquoise was represented, including an example of the rare and controversial white turquoise, which many argue is not turquoise at all. I will not settle that argument here, but the NBMG did write that turquoise colors could range to almost white and grey. After too short a stay, I hustled out of the visitor center to get to the Mizpah lobby by ten o’clock.
In the Mizpah a small group of us filled out paperwork, were issued a yellow nylon bag for our findings, and were introduced to the personable Dean Otteson. He seemed genuinely interested in sharing his life and his love of turquoise. A family affair, no less than 13 Ottesons have active claims in the Royston Mining District. We would caravan to the claim, he said, so the six of us went off to our three vehicles. We gathered in front of the Mizpah and were soon racing out of town.
And I do mean racing. After a short stint on I-95 West, we headed northwest on Gabbs Pole Line Road at a furious speed. We passed SolarReserve’s power plant, whose thousands of mirrors concentrated sunlight on a tower receiver that glowed like a torch. Our small convoy struggled to keep up with Dean’s truck. After twenty miles we broke westward over an unpaved but well graded road toward the Royston Hills. Rain had fallen in previous days but our entourage, a low- slung sedan, a full-size pickup towing an ATV, and my pickup, managed to battle through the occasional wallow. I tried not to think about damaging the paintings and possessions in my truck, the load I was taking to Las Vegas. They would have to take care of themselves – this was a time for turquoise!
After five or six miles on this unpaved track through desert scrub we came to our first stop a few hundred yards from our final destination. Dean pointed out an abandoned mine that at one time supplied turquoise for Tiffany and Company. He said the old tunnel was safe to go into and that a mine room opened to the sky. Regrettably, in my haste to search, I forgot about these old workings and did not tour them before I left. After this stop I followed Otteson to his Royal Royston claim where we parked our vehicles. He motioned to a bank of overburden only steps away. It was in these spoils that we could search.
Dean’s excavator was following and exposing a main vein. As it dug through less promising earth, its bucket would swing back and place overburden behind the machine. That rock was then pushed away from the excavator so we could look through it. Armed mostly with hand rakes, we pawed at the material, turning over dusty rocks and rubble. I regretted not bringing a spray bottle.
Dean said the overburden was a jumble of kaolin shale and rhyolite. This matched my research; the USGS Nevada state geologic map shows the claim area belonging to the Havallah Sequence, Mississippian to Permian age rocks altered by volcanic activity. Fractured and fissured, the rhyolite was subject to turquoise producing seams and veinlets as the gemstone solidified.
Otteson told us to simply look for color. One big rock with a hint of blue caught his attention. Our group had only rock picks and hammers, nothing heavy enough to break open the piece. I said I had a hand sledge in my truck and that I would get it. Upon my return, however, the group had dispersed, each of them hunting on their own.
I looked over the rock, trying to read it. Not wanting to destroy something by blindly flailing away, I remembered Dean had said to hit the rock on the right. So, I did. A three-inch piece broke away, displaying good color. I hit the rock again and it cleaved open, exploding into a sky- blue color that matched any turquoise cabochon I had ever seen. A half inch thick vein of gem grade turquoise revealed itself – I was so excited that I wanted to put the rock into my bag immediately and run off with it. But I hesitated.
Our group found the rock together. I therefore considered it a community rock and so, wistfully, I placed it next to my tool bucket. Later, we would all have to figure out who got to keep it. And while the group had scattered, my prospecting experience taught me never to leave a productive area until it was exhausted. I was soon rewarded for staying close with specimens that showed wonderfully what I had read about while getting ready for the dig: turquoise veins shot through parent rock.
Click TWICE on a photo to see it full size.
These new pieces showed fracture lines and veins more clearly than the first rock but with much less turquoise. I said to Otteson that while interesting, they didn’t seem to be good prospects for working up. He disagreed, saying that it depended on the skill of the rock cutter, that if done properly a good show could result even from these thin veins. I later read about ribbon turquoise and how a narrow line of color through country rock could produce a beautiful cabochon. Otteson was clearly an expert.
Dean asked me how splitting the first rock had turned out. He gave a big smile when I brought it over. I told him I would have to figure out who would get to keep it. He regarded me with a puzzled look, as if to say not to worry about it. Fortunately, a member of our group overheard our conversation. He shouted, “Tom, just keep it!” I happily put it in my yellow bag, already thinking where I could display it in my new home.
One of our company found a round and dense green stone that looked quite gemmy. I hadn’t read that the Royston Mining District produced nodules or nuggets, never-the-less, there it was. I read later in Pearl’s Turquoise that when “a rock cavity is only partially filled, the surface is often rounded.” The others in our group were also equally happy with their finds, mostly hand sample sized rocks showing green and blue.
Having found enough rough to keep me happy, I and several others walked down to where the excavator was used to chase the main vein. Moments before, I had seen Dean’s brother and another hand leaving the mine with five gallon buckets of rough. It all looked very blue. Almost canyon like, a high rock wall loomed over a deep hole that the excavator was burrowing into. The mine had been producing for some time judging by the depth of the pit.
We spent about three hours on the claim. It felt special to walk around a working mine like this on such a beautiful fall day. Otteson encouraged all of us to join a rock or mineral society in our home towns, so we could work our turquoise and find out more about rocks and gems in general. Good advice. For those without access to saws, Otteson offered to cut smaller pieces back at the Mizpah.
Feeling recharged by the experience I drove back to the main road at my own pace, enjoying the countryside. The glow of SolarReserve’s tower shone in the distance, leading me to the main highway and from there on to Las Vegas. I thought about the Margrave turquoise collection I saw in Reno at the beginning of my trip. Perhaps, I, too, could start a Nevada collection. Perhaps my turquoise odyssey was not ending but only beginning. What a feeling!
III Access and Amenities
The William M. Keck Earth Science and Mineral Engineering Museum is located in the Mackay School of Mines Building on the campus of the University of Nevada at Reno. Handicap accessible with restrooms. Nearby parking is metered and scarce when students are in session. A long walk is often needed. If you have mobility issues, take a Lyft or an Uber or taxi from downtown Reno and get dropped off as close as you can to the Museum. No admission charge. (775) 784-1766.
The Great Basin Science Sample and Records Library building housing the Nevada Bureau of Mines and Geology sales office is located at 2175 Raggio Parkway in Reno. Handicap accessible with restrooms. Plentiful parking. No charge. (775) 682-8766.
The Tonopah Historic Mining Park is located at 520 Mculloch Avenue in Tonopah, immediately behind the Mizpah Hotel. Good parking for most RVs and trailers with an easy pull-through. Visitor center and mineral display room is handicap accessible and has restrooms. Free admission to the visitor center, its store, and the mineral displays. The grounds are not easy for the physically challenged, however, depending on staffing, they may be able to run you around on a Gator. There is a fee for that; inquire. No charge for the store or museum. There is a charge for the walking tour which ranges from $3.00 to $5.00. (775) 482-9274.
NB: Check my file on Places to Visit and Collect in The Southwest for the most current information:
The Mizpah Hotel is located on 100 North Main Street in Tonopah. Handicap accessible with restrooms. No microwaves or mini-fridges in rooms. Coffee provided on each floor in the morning. Corner rooms have great windows, some of which may need help with opening. Claw foot bathtubs common. Restaurant, bar, and lodging. (775) 482-3030.
Click TWICE on a photo to see it full size.
Royston Turquoise Mine tours are arranged and conducted by the Otteson family on Wednesdays and Saturdays from April through October. (775) 482-9889. The claim site itself is unpaved, uneven ground and without facilities. People are escorted in but can leave by themselves. Going? Bring water, snacks, goggles, gloves, a spray bottle and a rock hammer. Check their website for additional items. Perhaps a rented vehicle if you are concerned about your car. Good luck!
November 12, 2019 Update: The Ottesons are again offering fee digs to the general public:
bankofoverburden.jpg: Group members with their issued yellow bags collecting on the overburden bank at the Royal Royston claim.
cabinetsizerock.jpg: This washed three-pound cabinet size rhyolite rock shows a gem grade turquoise seam.
deanOttesonpointing: Royal Royston claim owner Dean Otteson pointing to a possible find in overburden.
excavatorchasingthemainvein.jpg: Excavator at the Royal Royston claim removing overburden of rhyolite and kaolin shale to expose the downward trending turquoise vein.
greenblueturquoisehandsample.jpg: This washed hand sample was typical of the size of blue, green, and blue-green stones found at the Royal Royston claim.
greenturquoiserough.jpg: Low grade green turquoise in rhyolite at the Royal Royston claim.
luellamargraveturquoisecollection.jpg: Luella Margrave turquoise collection at the W.M. Keck Earth Science and Mineral Engineering Museum in Reno.
NBMGRoystonDistrictmap.jpg: The Royston Hills Mining District lies approximately 24 miles northwest of Tonopah, Nevada and it straddles Nye and Esmeralda Counties.
[Note. NBMG materials are not copyrighted, however, they do require a credit line.]
rhyoliteandkaolinshale.jpg: Country rock of rhyolite at the bottom with an overburden of kaolin shale at the top.
roystonturquoisejewelry.jpg: Navaho jewelry with Royston turquoise exhibiting rhyolite matrix.
[Note: Adobe Stock image purchased by myself. No royalty or credit required.]
townoftonopah.jpg: View of Tonopah facing west as seen from the Tonopah Historic Mining Park.
turquoiseseaminrhyolite.jpg: Turquoise seam deposited in fractured rhyolite.
viewfromthedash.jpg: Looking east to the Ione Valley from the Royston Hills Mining District.