From The Striped Hills

Acting on a non-ferrous signal from a rock in a wash near Lathrop Wells, Nevada, I moved upstream to see if I could find the source of whatever metal was causing my detector to ring out.

There were no records of any commercial mines in the Striped Hills near Lathrop Wells, however, there were passing mentions of old copper prospects in the area. These are limestone hills and I didn’t think of them as producing any metallic ore from uplifted seabeds. Where would copper come from by way of calcium carbonate shells and the skeletons of ancient sea creatures?

Update: Actually, there are carbonate or sedimentary based minerals. Azurite and malachite in the copper group can definitely arise in a sedimentary location,  given the right conditions. As RC with Geological Specimen Supply explained to me, “Limestone against granitics often gives rise to a contact deposit. If the granitic is quartz monzonite, the mineralization is often copper.”

There are were some volcanics in the area, however, as I noticed when I first got out of my truck. Quartz pieces were scattered here and there. Most quartz arises from molten magma. Volcanic activity.

These exploratory diggings proved very difficult to find as the road to them had long been cut to pieces by countless desert storms over the decades. An ATV might make it in, but first you have to know where you are going. To find out, I set out hiking on foot with my tools, just as I have done with most of my gold prospecting.

I had GPS coordinates for some of these ancient claims but a GPS fix on an old mine is likely a conversion from the Public Land Survey System which does not use latitude and longitude. That means you will probably wind up in the middle of a claim area, which could be twenty acres in size, not at any particular excavation or tunnel entrance.

The result was that I spent three half-days hiking up and down over many steep hills and on treacherously slippery, broken rock. This was mostly highly fractured quartzsite, a metamorphic altered from slate and before that shale. All first arising from ancient seabeds now raised up. Tough. Seen tougher.

I eventually found some pretty rocks as the last picture shows, however, all of them are essentially coatings like chrysocolla. The greener material leans toward malachite and chrysocolla, the bluer toward azurite. Nothing I found rang out like what I found in the desert wash that drains this area. By way of comparison, the copper mineral group member bornite definitely rings my detector as well as, of course, native copper.

I noticed a tremendous amount of black sand on the hills I hiked. All of it proved sterile when I processed two buckets of sand and gravel. To be fair, I didn’t have any fire assayed so I don’t know for sure. Processing microscopic gold, however, is for large scale operators. I will be back, though, if not for the minerals, then for the peace and quiet.




















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Quartzsite is Coming Soon!

Quartzsite in Arizona is coming alive for the season right now. Make plans now to get there, if you haven’t done so already. The culmination of rock related activities related in Quartzite will be the 2020 QIA PowWow, a four day show that starts on January 15th and ends on January 19th. But Desert Gardens will get started January 1st as well as lots of other venues. More below.

I recommend staying two full days in Quartzsite  if you haven’t gone before. Lodging is extremely limited in town, however, you can sleep in your car in the desert. Are there any other questions? Oh, okay.

The article below is the fifth piece I wrote for Rock&Gem Magazine. It appeared in the April, 2017 issue and it is here now due to the gracious consent of the current managing editor, Antoinette Rahn.

I’ve updated information where necessary and made good the links. There is additional material at the end of the article which comes from my Places to Visit and Collect in The Southwest file. Good luck, I will see you there.

Quartzsite: Rockhounds Gather in The Desert

by Thomas Farley

Quartzsite, Arizona is a town and a meeting place. In winter it is a gathering of the clan for recreational vehicle Snowbirds, flea market enthusiasts, ham radio operators, off-road motorists, geo-cachers, and rockhounds. Especially rockhounds. Quartzsite is rock and gem heaven.

While many Quartzsite locations sell rocks in the winter months, the biggest production is January’s QIA PowWow Gem and Mineral Show. In 2017 it featured over 550 spaces and 272 vendors. Put on by 300 volunteers, seller’s wares had to be 75% gem, rock, mineral, or jewelry related. Running concurrently with the PowWow at another site, the Desert Gardens Gem and Mineral Show concentrates mostly on rocks, with a little less jewelry than the PowWow. Then there’s the Tyson Wells Rock and Gem Show. And the Prospectors’ Panorama. But I am getting ahead of myself.

Quartzsite is in southwest Arizona, 244 miles east of Los Angeles and 127 miles west of Phoenix. Las Vegas is 213 miles to the north. Located in the La Posa Plain, La Paz County, Quartzsite is bordered to the south by the Dome Rock, Castle Dome, and Kofa Mountains. In its heyday, 39 mines operated around Quartzsite. Mostly gold mines, with one or two cinnabar and lead. A profusion of old mines and collecting sites gave rise to Quartzsite in the mid 1960s as a rockhounding paradise. Quartzsite’s population now stands at roughly 3,000 people.

In 1856 Charles “Charly” Tyson dug a well that would provide water to cross country travelers, nearby ranchers, and to mine workers in the surrounding mountains. He built a small adobe structure and called it Fort Tyson. It eventually became a stagecoach stop on the route from Ehrenburg, Arizona to Prescott. By that time one building had become several, the compound taking on the fuller name of Tyson’s Well Stage Station.

Quartzsite owes its present appellation to postal naming conventions. The postmark “Tyson’s” served the town until 1895 when mail service ended due to the local postmaster falling ill. A new post office opened in 1896 at another location. The Postmaster General decreed that discontinued place names couldn’t be used and, further, only one-word names were acceptable. Quartz Site is what the townsfolk wanted, from all the quartz at a nearby stamp mill. The postal service shortened it to Quartzsite.

The PowWow Gem and Mineral Show first started in 1967 with 18 locals selling items at a small school to about a thousand people. The event progressed into what may now be the largest public rock and gem show in the country. Over these fifty years the entire town has become dotted with rock shops, auction houses, and trading posts of all kinds. While I was there a venue announced the sale of a pallet of American flag products, 4,000 helium balloons, and over 10,000 old Playboy magazines. Essentially, if something has been made, it’s probably been sold in Quartzsite.

Quartzsite’s popularity as America’s largest yard sale and winter retreat probably peaked in the year 2000. In January of 1999, Huell Howser, California travelogue producer par excellence, took his film crew outside the state for the first time to cover Quartzsite. In a warm and engaging hour, which is free to view online, Howser interviewed many townsfolk, mostly about the history of the community. Then, in 2000, National Geographiccame to visit. They called Quartzsite Nowhere, Arizona. Until November:

“Then, like a mob of chattering starlings settling into a too-small tree, the snowbirds start landing in November. By mid-January, the mechanical car counter at the Interstate 10 exit is ticking off 26,000 vehicles a day. Within weeks 175,000 RVs cram inches apart into 79 trailer parks, onto front yards, and spill out seven miles on either side of town. Every year more than a million people reset their internal navigation and drive from Everywhere, North America, to this western Arizona dot on the map. Luxury motor homes, fifth wheels, cab-over campers, trailers, and converted school buses plunk down on the same patch of land.” “America’s Largest Parking Lot” by Cary Wolinsky. National Geographic, January, 2001.

Things have settled down since then. My visit started on Wednesday, January, 18, 2017. Empty RV parking spaces in town seemed numerous. Space looked plentiful at BLM land outside of town. But since few venues charge for admission or parking, there’s no real way to keep count. The BLM did tell me approximately 28,401 people stayed at their free and pay areas in fiscal year 2016. And the Arizona D.O.T. says Main Street now averages 12,400 vehicles in each direction over the course of a year. The city website says 2,000,000 annual visitors. Whatever the numbers, the rock shows continue to draw vendors in record amounts, with waiting lists common for spaces.

As to the PowWow itself, Wednesday was ideal. Bright sunshine and short sleeve weather. I regretted not bringing sunscreen and I later bought a hat from the Quartzsite Gem and Mineral Club. More on them in a bit. To begin with, the PowWow is located just off Main Street at 235 East Ironwood Drive. Follow the cars. A parking lot doesn’t seem obvious, but keep moving along and you’ll find it; everything funnels to the main lot. Two tractor pulled shuttles take visitors to any entrance they like. Drivers give everybody time to get on, including those with walkers. Shuttle, parking, and admission are all free.

I came simply to look around, this being my first time in Quartzsite. Listing everything I saw would be like reciting a lengthy gem and mineral guide. Items varied from Bruneau jasper to lapis lazuli to malachite to Oregon sunstone. One booth sold “Hot Rocks”, with a Geiger counter next to them in case you had doubts. Another vendor had over a hundred sample boxes filled with different rocks and minerals, all arranged in alphabetical order. 21 boxes under “C” alone. That assortment ranged from Terlingua, Texas fluorescent calcite, to Coontail quartz from Magnet, Arkansas, to coyote teeth from British Columbia. And that was just one seller’s table.

A dinosaur sculpture greeted me on one aisle. On the next, oil paintings on marble. As I wandered, I came across Timothy Harned’s tables. He owns Bustin’s Glass and Minerals. I last saw Tim at the 2016 Logandale Fall Festival in Logandale, Nevada. The promoters advertised a Rock and Gem Faire at the event but Tim turned out to be the sole vendor. It was good to see him again and we talked. Again, Quartzsite is a meeting and gathering place.

The QIA building is PowWow’s center. QIA stands for the Quartzsite Improvement Association. Within their building is a limited number of dealers, display cases, and the kitchen and dining hall. Food is sold throughout the day, with all proceeds going toward supporting the QIA and its many community causes. The dining hall makes a great place to reconnoiter with your group, study the vendor list, and then plan what to see next.

The PowWow in 2017 ran from January, 18th until the 22d. As I mentioned, the Desert Gardens Rock, Gem, and Mineral Show was running concurrently and through February 28th. This venue is on the other side of I-10 at 1050 Kuehn Street. It has no parking lot shuttle service. A walk around Desert Gardens was similarly staggering, especially because of larger material. This is the place to find big pieces of rough. Need a spectacular garden rock? You’ll find it at Desert Gardens. The Desert Gardens venue was less busy than the PowWow and had a more relaxed feel. You should visit both. But the appeal of Quartzsite extends beyond the rock shows, to dedicated rock and gem shops and to the clubs that operate throughout the winter. First, the clubs.

The Quartzsite Roadrunner Gem and Mineral Club is one of the largest and most organized rock clubs in the country. Membership is only $15 a year and they are active October through March. Field trips go every Tuesday through the season and twice a day during PowWow. Non-members pay $2 a trip. Roadrunners this year during PowWow went to find bacon rock, desert roses, geodes, apache tears, and green banded rhyolite. Among other things. Round trip mileage ranged from 40 to 162 miles over a variety of roads, many of them tough. http://qrgmc.org

The Quartzsite Metal Detecting Club consists of coin shooters and gold prospectors. Membership is a terrific bargain at $20 a person. This lets you in on the club’s 14 claims encompassing 280 acres of gold bearing ground. The club is most active November through the middle of March, however, you are free to work in summer if you can stand the 118 degree heat. If you are a coin shooter, you can participate in their many winter season hunts. $20 for each hunt.Do not mail your dues to them, instead, pay in person at the Miners Depot described further on.

http://quartzsitemetaldetectingclub.com/

I stayed in Quartzsite for three days, however, with so many club activities, a week would have been a better choice. And then there are the stores.

Quartzsite is peppered with stand-alone and pop up stores selling rocks, gems, and minerals. Quartzsite’s business and souvenir map reveals retail shops like Gem World, T-Rocks, Sunwest Silver, and, less obvious, Hardies Beads and Jewelry. That last store is a Quartzsite institution. While mainly selling collecting supplies and beads, they have an outstanding rock collection installed on their interior east wall. Their museum contains quite a few specimens from the Quartzsite area, including gold in quartz. See the image below.

For gold prospectors, make certain to stop in at Blake and Lisa Harmon’s Miners Depot on North Central Boulevard. Miners Depot is a desert prospecting store and the unofficial clearing house for gold information in the Quartzsite area. Inquire about the metal detecting club. As with everything in Quartzsite, hours are seasonal.

http://www.minersdepot.com/

While shopping, don’t miss a chance to visit the Tyson’s Well Museum. It’s free and enthusiastic volunteers will tell you the history of Quartzsite as a stage station and a supply depot for nearby mines. Speaking of which, outside in back, is the original assay office of the Mariquita mine. The many items speak to the everyday life of miners. The volunteer I talked to was also a member of the metal detecting club. He discussed at length the many mines surrounding Quartzsite. Be sure to notice the museum ceiling made of saguaro ribs.

Other winter shows include:

The Prospector’s Panorama:

(http://prospectorspanorama.com/),

Tyson Wells Rock and Gem Show:

https://www.tysonwells.com/rock—gem-show.html

The Gold Show.

https://quartzsitegoldshowcom.wordpress.com/)

Desert Gardens — lots of big rough there, see picture below:

http://desertgardensrvpark.net/DGShowRGMShow.html

Quartzsite doesn’t take itself too seriously. The square dance club is called the Cactus Dodgers, a propane supply company is called Passmore Gas, and one street is named, well, No Name Street. Camel references abound and you should know the story of them and of Quartzsite’s most famous citizen before you visit.

In 1857 the War Department directed Edward Beale to pioneer a wagon trail from New Mexico to California. In his company were about 75 camels purchased from North Africa and the Middle East. This constituted a great experiment as to the worthiness of camels as pack animals in the great Southwest. Questions were many, such as, could camels swim the Colorado River? On this journey as packer and guide was one Phillip Tedro, born in present day Turkey and later a Syrian countryman. After converting to Islam, Tedro called himself Hadji Ali. The men in Beale’s company had difficulty pronouncing the name, however, and instead called him Hi Jolly.

After completing the journey, which Beale said went “without an accident of any kind whatsoever”, the troupe of camels were disbanded. (It Happened in Arizonaby James Crutchfield. Falcon Press, 1994) Speculation has it that the camel’s sensitive hooves, although perfectly suited to loose soft sand, could not endure the Sonoran Desert’s often rocky surface. A travel guide adds this, “The camels adapted well to their new environment but were never used successfully, partly because the sight of them caused horses, mules and cattle to stampede.” (AAA Arizona and New Mexico Tour Book, 2014)

Hadji bought a few camels from the company and returned with them to Arizona, where he engaged in various pursuits, including mining and acting as a government scout. He became an American citizen, married in Tucson and finally settled in Quartzsite. At a certain point he released his camels to the desert. He died in 1902 and is buried in Quartzsite’s cemetery. In 1935 the State of Arizona built the pyramidal Hi Jolly monument which you see today. According to the 2017 Quartzsite Visitor Guide , it is the town’s most visited spot. The legacy of camels echoes throughout Quartzsite in postcards, sculptures, and as ornaments in maps and guidebooks.

At any booth you’ll find miners who found and worked up material from their own property or claim. It is this direct connection that makes buying more personable than purchasing a rock through eBay or another second hand source. Two talks with vendors were memorable.

Karen Britton of Britton Apache Turquoise has been mining and working variscite and turquoise for 29 years in central Nevada in Lander County. Her late husband, Lee Britton, had even earlier ties to turquoise and turquoise like rocks. He first staked a Lander County claim in 1974. Their most famous property was the Apache Turquoise Mine. Karen mentioned a Rock&Gem article done by Mark Hatch where he described how he produced a stunning necklace starting from Apache Mine rough. (“Make an Apache Turquoise Necklace” by Mark Hatch Rock&Gem January, 1971). I read the piece later and it was indeed a tribute to the black included stones Britton regularly mines. I bought a cabochon from Karen, partly as a collectible, partly to support her continuing efforts.

After the show I read up on the Apache Mine. Two writers wrote that Apache Mine material once thought turquoise has now been identified as variscite. (Minerals of Nevada, Stephen B. Castor and Gregory Ferdock. Nevada Bureau of Mines and Geology Special Publication 31, 2004.) What impressed me on that Wednesday, however, was Karen’s dedication to her beautiful rocks. She soldiers on with no web presence, appearing only at shows like those in Quartzsite. Besides talking to this veteran, I was also struck by a young couple just making their presence known in the rock business.


John Keady and Chelsea Thompson operate Rockchuck Gem and Mineral Gallery in tiny Schurz, Nevada. It’s just north of Walker Lake in Mineral County on I-95. The pair create cabs and jewelry, notably using turquoise and variscite from different Nevada locales. They also mine their own Hellsfire agate. Keady is by training a stone mason. I didn’t know all this until I came across their booth. I vaguely recalled a rock shop sign near Schurz but I never investigated it. And now, here were the owners. The shop had come to me. There’s more.

The last time I passed Walker Lake I stopped to read different information signs. They were installed on impressive monuments made of local stone. It turns out Keady built one. What were the odds I’d meet the builder of something I noted on a lonely road to Reno? And what were the chances I’d run into two such young and creative people almost six hundred miles from their home? As I said before, Quartzsite is a gathering and meeting place. For people you’ve already met. And for the people you will.

Some Quartzsite Tips

Many sellers and restaurants take only cash so be prepared. The only bank in town is the Horizon Community Bank. Take a notebook to keep track of purchases, vendors, and details. Bring sunscreen and a cap. A raincoat and a heavier coat for rain and wind that may well happen. Don’t forget your loupe and a camera. Remember, too, that Arizona is on Mountain Standard Time. Most things get going around 10:00 a.m. And look out for pedestrians while driving at night. They are everywhere and all dressed in black. One more thing. Bring your patience — you’re among friends.

Essential and mostly free publications to pick up around town:

Quartzsite, Arizona Visitor Guide

Quartzsite EZ-Guide (a map of vendor spaces for the four major shows)

QIA PowWow Gem and Mineral Show Guide (available at the PowWow)

The Quartzsite Nugget and Winter Visitors Guide

Where IZZAT Business Map (Absolutely vital for navigating Quartzsite. $2.00)

Desert Messenger News (Community paper)

Most publications won’t be available until the end of the year. Until then, keep abreast of Quartzsite happenings with the excellent Desert Messenger. Read it here:

http://MyQuartzsite.com

Consult the Quartzsite Area Chamber of Commerce and Tourism: http://www.quartzsitetourism.com.

Lodging. Very limited in town.

Super 8, Quartzsite: (928) 927-8080. 2050 Dome Rock Road. Quite far from town but the biggest motel. Two stories. No elevator. Book before October.

https://www.wyndhamhotels.com/super-8/quartzsite-arizona/super-8-quartzsite-az/overview

Quartzsite Yacht Club: (928) 927-5628. 1070 West Main Street.

http://www.quartzsiteyachtclub.com

Stagecoach Restaurant and Motel
(928) 927-8161
904 West Main Street

No true web presence. Call.

People also stay in Ehrenberg, AZ or Blythe, CA, about 18 miles and 22 miles away, respectively. Parker, AZ is about forty miles north on I-95 but the road crosses many washes and could be cut off in a rainstorm. Still, I like the drive and often stay at the Hampton Inn in Parker.

A Yelp list of RV Parks is here:

https://www.yelp.ca/search?cflt=rvparks&find_loc=Quartzsite%2C+AZ+85346

Camping in the desert? Here’s one BLM link:

https://www.blm.gov/visit/la-posa-long-term-visitor-area

MORE DETAILS!

Quartzsite, Arizona – City and Major Rock Event

Quartzsite comes alive in winter. January sees a gathering of rock, gem, and mineral collectors and sellers from all over the world. I’ve written about this extensively at my blog, https://southwestrockhounding.com. See you there in January.

Quartzsite Museum aka the Tyson’s Well Stage Station

161 West Main St
Quartzsite, AZ 85346
928-927-5229

33°39.971′ N 114°13.182′ W

https://www.visitarizona.com/business/quartzsite-museum

Mining artifacts and assay office. Seasonal hours. The Tyson’s Well Museum is a must-stop. It is free and enthusiastic volunteers explain the history of Quartzsite as a stage station and a supply depot for nearby mines.

Hardies Beads & Jewelry

1250 W. Main St
Quartzsite, AZ 85346
928-927-6381

33°39.754′ N 114°14.256′ W

http://hardiesonline.com

Outstanding rock, gem, and mineral collection on display. Most material collected locally. Not many rocks for sale, mostly things bead related. A Quartzsite institution.  Seasonal hours.

Quartzsite Roadrunner Gem and Mineral Club

Headquarter Address:
65 Ironwood, Quartzsite, AZ (Quartzsite Improvement Association building)

33°39.925′ N 114°12.843′ W

Mailing Address:
PO Box 338, Quartzsite, AZ  85346
928-927-5531

http://qrgmc.org

The Quartzsite Roadrunner Gem and Mineral Club is one of the largest and most organized rock clubs in the country. Extremely active, especially October through March. Field trips go every Tuesday through that time and twice a day during the QIA’s PowWow. Non-members pay $2 a trip. Roadrunners may go to find, among other things, bacon rock, desert roses, geodes, apache tears, and green banded rhyolite. Major shop facilities and classes.

Miners Depot

566 North Central Blvd
Quartzsite, AZ 85346
Messaging through their website

33°40.538′ N 114°13.033′ W

Miners Depot is desert prospecting store and a clearing house for gold information in the Quartzsite area. Detectors, tools, screens, lots of screens, the place to stop before heading out. Generally open six days a week during the main prospecting season, from about November through mid-March.

https://minersdepot.com/

Quartzsite Metal Detecting Club

Mailing Address
PO Box 3102
Quartzsite, AZ 85359-3102
928-927-7150
Meeting address (Miners Depot)
566 North Central Blvd
Quartzsite, AZ 85346
33°40.538′ N 114°13.033′ W

A club of coin shooters and gold prospectors. Membership is a terrific bargain at $20 a person. This lets you in on the club’s 14 claims encompassing 280 acres of gold bearing ground. The club is most active November through the middle of March, however, you are free to work in summer if you can stand the 118 degree heat. If you are a coin shooter, you can participate in their many winter season hunts. $20 for each hunt.

Of special note, they do not mail memberships. Sign up and pay dues at their club meetings, coin hunts, their table at the PowWow in January, and at Miners Depot. Really, though, get out to Miners Depot. It is well worth your visit.

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Mystery Crystals Revealed as a Mystery

Results

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 website:

http://kaygeedeeminerals.com/sem-eds_service

His Etsy store, under the name KGDOLMC, is here:

https://www.etsy.com/ca/shop/KGDOLMC?

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! 🙂

—-

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Recent Field Trip Update

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.

Tuff Near Jean, Nevada from Thomas Farley on Vimeo.

And here I am at point of discovery, thinking I had stumbled upon quartz crystals. This area had gotten much richer in mica as I walked toward it, indicating increased mineralization.

Sanidine crystals in tuff? Near Jean, Nevada from Thomas Farley on Vimeo.

Hand samples.

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.

——

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Version Five of Southwest Places to Visit and Collect is Out

I’ve made a substantial revision to Version 4. The interactive table of contents continues to be built out. More clubs, more Google Map links to make for easier driving. Discard all previous versions.

1. The Acrobat .pdf file is essentially bulletproof. Great for printing and desktop work. Download here:

SW_Places_To_Visit_Or_Collect_05_

 

 

 

2. The Kinndle .mobi file is for mobile use. Anyone with a Kindle app or reader on their phone or tablet _should_ be able to use it when downloaded from here but I can’t guarantee it.

SW Places To Visit Or Collect 05 – Tom Farley

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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, 2019

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, 2019

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.


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



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.



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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Last Note From Plymouth: Siderite Sighting?

NB: Thanks to a kind German researcher whose inquiry prompted me to update this page.

Tuesday, April 30th. 2019

My mistake. Not siderite. Thanks to everyone who tried helping.

Had a great talk about my mystery rock with two people at the Geosciences Department of University of Nevada at Las Vegas here in town. Kind and informative folk. What follows is NOT the exact wording of what they told me, rather, my interpretation of their remarks as a collector and a rockhound. Any mistakes or poorly put remarks are my own.

For background, the relevant map is the Preliminary Geologic Map of the Irish Hill 7.5 Quadrangle, Amador County, California. The loose rock I carried in, as well as the larger outcropping I have photographs of at my website, is at the contact between two parts of what is called the Gopher Ridge Volcanics, Jgo, and Jgof, respectively.

This is from the map:

Gopher Ridge Volcanics (Late Jurassic)—Named by Clark (1964) for exposures along the Calaveras River south of the quadrangle. Consists mostly of massive mafic and intermediate tuff, breccia, and occasional greywacke and agglomerate. Likely Oxfordian in age (Clark, 1964). Includes felsic facies (Jgof) that was originally mapped as quartz porphyry by Turner (1894) and Taliaferro (1943).

After careful examination and handling of the large rock and associated small samples showing the interior of the rock, these are some of their observations.

1. Streaks red for hematite. Rock most likely an association of hematite and goethite.

(I hadn’t streak tested because it seemed the powdery, iron-rich red coating cold only produce a red streak)

2. The large rock seems severely eroded on one side by preferential weathering.

3. A thin quartz vein appears to run through the width of the large rock.

4. Some of the large rock may have originated as a conglomerate and was then altered heavily by hydrothermal activity.

5. My microscope photographs of the interior, showing a botryoidal texture, are exactly what they would expect given the texture of the rock’s exterior.

6. Isolated outcroppings like this may exist  by themselves without like them around. It is possible other material like this is below the surface, covered.

7. Not slag or manmade occurrence

That’s all I have for now. A beautiful outcropping that certainly deserved the time to be looked at and discussed. A suggestion was made to saw the large rock into two pieces and I am thinking about it. The rock may yet reveal more.

Side note. These were Rolf’s comments which the people at UNLV found informative:

Hi Tom,

From Rolf  Luetcke:

I looked at the photo you sent and to me at the lower left I saw something that to me looks like goethite. It is a seam and a bit hard to see in the photo but it looks to me like a fibrous inner structure to the seam. To me that means goethite. Could be a mixture of the iron oxides, which wouldn’t necessarily give a metal detection on equipment but sure seems like a botryoidal iron, either goethite or hematite-limonite.

Dear Rolf::

I think you may be onto something. Under my 10X loupe I can see what are definitely threads or fiberous material that looks like thick strands of hair. The Geosciences Department at the University of Las Vegas has asked me to bring in any info I have on the rock so I will print out your thoughts. There is a picture of goethite with hematite at Mindat that looks like my rock, although the specimen photographed is quite small. Now, the most important question, how does one pronounce goethite? Is it gur-tite or something else?

Here’s photo showing botryoidal  texture on the interior:


 


ORIGINAL POST:

This odd looking lump is on my friend’s horse ranch on Carbondale Road, outside of Plymouth, California in rural Amador County. Near the center of California’s Mother Lode Country. I wrote about this place in a previous post. The soil is nondescript, red foothill clay, with the most common rock underfoot being broken pieces of iron stained quartz.

And then there is this thing, which my first guess was a bunch of leftover concrete that someone had attempted to color. Perhaps they dumped out their concrete mixer at this spot? There is no sign of any unusual concrete work in the area, but who knows? I did not have my rock hammer as I was traveling and renting a vehicle.

Usually concrete aggregate has much smaller stones than the blobs we see here. I am up to any guesses. There is a creek nearby with what I presume are rounded stones but it is not on my friend’s property so I haven’t checked it out. I can’t imagine anyone making their own concrete with locally collected rock, think of the work, but I suppose it is possible.

Another possibility is siderite, which Mindat.org lists as being in the general area. A nice man named Brice on the Facebook group, Rocks and Minerals – identification and information, made this suggestion.

Siderite is an iron mineral, of which I am only now reading about. Apparently, siderite is valuable mineral in theory since it contains a high amount of iron, possibly 48%. In such a small outcropping it is totally uneconomic but an interesting curiosity to any rockhound or mineral collector walking the woods. Its presence may lead to the discovery of other nearby minerals such as manganese.

The odd looking lumps may be large siderite crystals that have weathered to their present shape over time. More on that below.

 

This is an overall view of what I will call for now, the outcropping. For a much larger picture to ponder over, click here. Or click on the photo itself.

 

Closeup photograph. Pen for scale.

 

A damaged or otherwise altered section of the outcropping. Broken concrete doesn’t turn black, it retains a whitish color due to the Portland cement. If the concrete were mixed with a colorant originally, however, in the drum, the color would run throughout the mix.  But you would have one color, and not two as in the photo. An iron ore deposit just might make sense. The outer layer has weathered and oxidized red, rusted if you will, while the more newly exposed material has yet to change.

 

The above picture is courtesy of Dennis Miller. Used with permission. It’s siderite from an area near Chihuahua, Mexico. Note the globular forms. I’m speculating that the globular material in the outcropping I came across are weathered, eroded permutations of this siderite’s original form. Or not.

The Henry Holt Guide to Minerals, Rocks, and Fossils (very British) says that siderite crystals can be, “[M]assive, fibrous, compact, botryoidal, or earthy.” The outcropping seen here is definitely botryoidal.

The book goes on to say that massive siderite is widespread in sedimentary rocks. There are notable, economic clay deposits several miles distant, which leads me to this quote from Holt’s book.

“Massive siderite is widespread in sedimentary rocks, particularly in clays and shales where it forms clay ironstones which are usually concretionary in origin.”

Concretionary. And an outcropping that looks like concrete. Iron stains every piece of broken quartz on the ground. So iron must be in the soil. Can anyone put this all together?

Mindat doesn’t show siderite as found in Amador County, however, these reports are usually confined to recording occurrences of economic value. Or a citation in the scientific literature. Like in a geology report. Not all outcroppings everywhere can possibly be recorded. Siderite has been reported in the county of El Dorado, immediately north, and Calaveras, immediately south. In the plant world, we would call an occurrence in a new area as a range extension. And you thought rocks and minerals had a peculiar vocabulary!

There is a mineral deposit of economic nearby, in fact, two. The named one is a copper deposit with the odd title of Mutual Life Insurance, Record ID 1016243. That can be looked up with the Mineral Resources Data System or MRDS. The closest point to these two spots is at the end of Poppy Hill Lane, which branches off of Forest Home Road. Although Google Maps shows some conflict with that, Poppy Hill being off of Long Gate Road.

I will have a friend test the outcropping with a magnet. That may be diagnostic. Although I see on Mindat that siderite is paramagnetic, a new term for me. It essentially means weakly magnetic. I’ll mail my friend one of my rare-earth magnets. Maybe that will make a difference in testing. I’ll report back later. Thanks, again, Dennis, for the photograph.

 

And here’s a citation to a paper that is beyond my understanding. The example labeled “D” is interesting. These are examples from Washington State. “Excrement-shaped masses of siderite and limonite have been reported from clay-rich sedimentary rocks . . . ” Click on the image for a larger picture. All the information is from the providing site.

 

Miocene siderite specimens from Salmon Creek, Washington. A, B, C, E, and G are coprolite-like extrusions that show pointed ends and longitudinal striations; D is a botryoidal concretion; F is an extruded mass with botryoidal encrustations.

 

Figure 3. Miocene siderite specimens from Salmon Creek, Washington. A, B, C, E, and G are coprolite-like extrusions that show pointed ends and longitudinal striations; D is a botryoidal concretion; F is an extruded mass with botryoidal encrustations.

Enigmatic origin of ferruginous “coprolites”: Evidence from the Miocene Wilkes Formation, Southwestern Washington – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Miocene-siderite-specimens-from-Salmon-Creek-Washington-A-B-C-E-and-G-are_fig1_249527075 [accessed 21 Feb, 2019]


The geologic map of the area, however, points to volcanic origins, igneous rock, not sedimentary. Minerals.net states that siderite can be in igneous, sedimentary, and metamorphic rock.

Preliminary Geologic Map of The Irish Ill 7.5 Quadrangle, Amador County, California:

ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Prelim_geo_pdf/IrishHill_24k_v1.0.pdf

Outcropping exists at the border of Jgo and Jgof.

From the geologic map:

Gopher Ridge Volcanics (Late Jurassic)—Named by Clark (1964) for exposures along the Calaveras River south of the quadrangle. Consists mostly of massive mafic and intermediate tuff, breccia, and occasional greywacke and agglomerate. Likely Oxfordian in age (Clark, 1964). Includes felsic facies (Jgof) that was originally mapped as quartz porphyry by Turner (1894) and Taliaferro (1943).

Note: af stands for artificial, man made workings. Outcropping not close. But what about forge slag? That would make this outcropping an archeological find, not a geological find, although the two would be related. Look at the picture below:

 

Source of the forge slag photo: http://bertan.gipuzkoakultura.net/es/16/en/1.php

 

Perhaps the “af” in the geological map suggests other former forge placements, these would have to date back to the gold rush era, certainly before electrical power was available to work iron ore in a modern forge.

Interesting photo from eBay below. “‘Siderite “Balls” with Calcite (Nikolaevskiy Mine, Dalnegorsk, Russia).”