Drew Barkoff: Friend of The Book

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting as much at this site. Instead, consider following me on Instagram, from your smartphone or desktop.

Handle: tgfarley

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do than blog posts. Thanks!


Drew Barkoff is a Ph.D. student at the University of Nevada in Las Vegas. He has been extremely helpful in all of my conversations with him, tolerating the questions of an unschooled writer. In his own words he describes some of the geological journey he has taken so far . . .

As for what part of the American Southwest interests me the most, the truth is all of it. Learning geology in NJ (effectively a massive sandbar) made me long for mountains and actual rock outcrops that weren’t a multiple-hour drive away. People living in the SW are geologically spoiled whether they know it or not, but I would argue that the Las Vegas, Nevada region is as good as it gets.

The LV region is centered between the Colorado Plateau and the Sierra Nevada, and situated within the Basin and Range province. This means that we have access to not only to rocks from a very wide range of earth’s history, but a number of different tectonic environments as well, ranging from the high-grade metamorphics of the coast belt in CA, to the middle- and upper- crustal sedimentary rocks in NV, to the igneous- and metamorphic core complex-rich rocks of Southern UT. Additionally, NV is the #1 state for mining, highlighting the fact that NV has some of the best mineralization in the county.

As for how I got interested in geology, it was a long-time coming. I have always been interested in the sciences, and chemistry in particular, something about how the complexities and processes of the natural world can all be described in a very ordered, logical manner through chemistry really appealed to me, it is the link that brings all the other sciences together.

When I first went to college, I thought I knew what I wanted to do for a career, and started my undergraduate Biology degree at Ursinus College, a small school in central PA. Within about a year, I realized that I was struggling and not enjoying the material at all, so I decided to search for another major in another field I was interested in. That summer, I took three classes at the local community college that interested me: Business and Economics, History, and Geology, with the goal of going the direction of whichever class I liked best for my new major. Needless to say, the geology class blew the others out of the water and I enrolled at another local school that Fall, Stockton University in NJ, and started my geology undergraduate degree.

My grades went from straight C’s and B’s to straight A’s, with seemingly little hard work, because I loved it that much. During my Junior year, my professor, Matthew Severs, asked me if I was interested in taking part in a research project, without thinking too much, I said yes. This critical moment is what changed the course of my life and academic career, and I am very grateful to Prof. Severs for the opportunity and seeing my potential. My research project involved determining the temperatures and pressures of pegmatite formation at the Oxford Pegmatite Field, Oxford Co., ME, using fluid inclusion thermobarometry, as well as determining the petrogenetic order of pegmatite formation.

Pegmatites, being some of the most spectacular sources for mineral collecting, really got me interested in the geochemistry behind their formation and what processes are capable of enriching them in many rare metals such as Be, Li, U, etc.. This project was successful and I felt confident enough in my research capabilities that I applied for a number of graduate schools during my senior year.

I was accepted to start a Master’s project at the University of Arizona, under Prof. Matthew Steele-MacInnis in the economic geology program. My Masters project focused on further developing a novel technique of using internal pressures developed by trapped mineral inclusions during cooling and exhumation to back-calculate the pressures and temperatures of formation. This method requires using Raman spectroscopy to quantify the internal pressures of the mineral inclusions (Raman peak location of different bonds are pressure-dependent) which can be used in combination with the compositionally-determined physical properties of the mineral phases involved to determine possible P-T conditions that may have produced their rocks, also using field relation constraints.

I loved the heavily analytical nature of this study but being in the Economic Geology department exposed me to the type of work the other students were working on, and needless to say, that interested me too. I knew I wanted to go in the direction of economic geology next because they are the ultimate example of crustal geochemical anomalies, so I applied to a few programs across the US and Canada that offer this program and I was lucky enough to be accepted to start my Ph.D. at the University of Nevada Las Vegas, under Prof. Simon Jowitt. Currently at UNLV, I am working on gaining a better understanding of the petrogenesis of evolved, topaz-bearing rhyolites in SW UT and their economic potential to be low grade, high tonnage resources of many rare metals such as the REE, Be, Li, and U.

As for what classes aspiring geologist can take to quickly gain a better understanding of geology, I would suggest physical geology (101 level class, might be too basic) and especially mineralogy and igneous petrology. Mineralogy gives you a very good (probably over the top for most people) understanding of mienrals, how they are constructed and the effect this has on what elements can make up their structures. Igneous petrology is a 2nd or 3rd year course but is easily understandable by anyone with a physical geology-level understanding. Igneous petrology really focuses on how crustal or mantle magmas form and how their evolution affects the geochemistry of these rocks. I think it best to start with igneous processes, then potentially moving onto sedimentary. And metamoprphic petrology because igneous petrology is the most applicable to most types of rocks, but classes exist for whatever your specific interest may be.

Regarding the fluorescent minerals, I don’t know too much about them specifically but many minerals can be UV fluorescent and it really depends on the formation conditions, and more importantly, geochemistry of the fluids that formed them. From what I know, the energy of the UV light is enough to excite certain transition metals within the mineral structure to jump to a higher energy state and then instantaneously dump this energy in the form of light as the electrons try to reach equilibrium again. I can actually look into some research on this if you would like an even more scientific explanation, this is quick-and-dirty explantion.

~Drew Barkoff

Wikipedia is A Starting Point. Only.

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting regularly to this site. Follow me instead on Instagram from your smartphone or desktop computer.

Handle: tgfarley

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do under deadline than blog posts. Thanks!


Wikipedia is best for references, not its original writing.

Compare these two paragraphs:

Wikipedia:

Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500-600 grams naturally occurring in Earth’s crust at any given time.

Los Alamos National Laboratories:

Searches for the element on earth have been fruitless, and it now appears that promethium is completely missing from the earth’s crust. Promethium, however, has been identified in the spectrum of the star HR465 in Andromeda. This element is being formed recently near the star’s surface, for no known isotope of promethium has a half-life longer than 17.7 years.

Wikipedia wasn’t dependable when it began but it is much better now. It has to be checked, though, like all research sources. Today, I see magazine articles written solely from online materials. This is disastrous. You need information from online resources, research from authoritative books and magazines, and personally gathered quotes from experts.

Anything else is lazy.

Double check.

Another research problem. Promethium’s density is likely undetermined, despite what this graphic and most sources state. I do not have enough certainty of that, however, to commit to this in print. When in doubt, say matters remain unsettled. A writer is not required to answer all questions.

Another Tool of The Trade: The Falcon MD 20 Gold Tracker

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting regularly to this site. Follow me instead on Instagram, from your smartphone or desktop.

Handle: tgfarley

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do under deadline than blog posts. Thanks!


The Falcon MD 20 Gold Tracker is a good tool but it often produces uncertain results.

As depicted in this video, here’s how the detector should work. The detector sounds when going _toward_ gold, silver, copper and so on. Non-ferrous stuff. Which includes aluminum and, unfortunately, too often, strong iron targets. Those overwhelm the detector.

This pet wood shown probably contains iron oxides, giving a signal when the probe moves _away_from the target. In the field it is often difficult to tell which direction in which a signal is coming from.

Rocks need minerals in enough quantity to test reliably. The detector responds better when something singular is presented, not a mix of different, weak, conflicting materials. Never-the-less, even with a conflicting signal, one knows a rock is metalliferous.

I do like it for many reasons, though, particularly when pawing through ore samples at a rock shop. There may be a bucket of rocks advertised as silver ore, for example. If those rocks are from a named mine then I am interested. I’ll use the Falcon to test each rock for a signal. Finding none I pass.

This is especially important when testing gold specimens. A flashy specimen labeled as gold may be pyrite. If so, it won’t trip the Falcon. In either direction of the probe. Pyrite doesn’t register on any quality metal detector. Or it is cancelled out. While pyrite is iron related, it is what’s called a sulfide and not fully iron by any means. It is too different in its  makeup to signal a metal detector.

Pyrite is often mixed in with gold but if one can’t see gold, and if a detector doesn’t register gold, then proceed with tremendous caution with any purchase.

If a mineral isn’t visible, I want that rock to at least respond to a detector. You’ll read nonsense about ore containing a mineral at a level above the crustal abundance. How do they know?

The Falcon is also good for testing rocks brought home from the field, ones not considered as metal bearing when collected. All finds should be eventually tested with UV lights, a Geiger counter, and a metal detector.

Burro Creek Campground Near Wikieup, Arizona

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting as much at this site. Instead, consider following me on Instagram, from your smartphone or desktop.

Handle: tgfarley

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do under deadline than blog posts. Thanks!


Burro Creek Campground, about ten miles or fewer from Wikieup, Arizona. This campground is base camp for rock clubs from as far as Utah. Agate is the main draw in the surrounding area, not at the camp itself. Potable water, first-come, first serve, the small group camp by reservation. $14 a night for the individual camp sites. Good pull throughs. Would advise smaller vehicles, ideal tent camping. No day use fee!

Creek is pretty but access is past narrowly spaced pipes, a nasty barbed wire fence encloses the entire campground. Good, clean water flowing right now. Great canyon setting, about 1,900 feet. Didn’t check cell coverage, I assume none. Anybody not enjoying rockhounding would still enjoy this campground.

View from the bridge over Agate Creek. Canyon invites exploring although get a BLM surface status management map of the area to show public land ownership.

The bridge abutments are  nicely done in Southwestern Art Deco style.

Don’t drive across the bridge with any large vehicle or a trailer in tow. Single lane dirt road beyond the bridge, I don’t know at what point you could turn around. Ask first. Logical place to turn around is the campground with its pull throughs in the Day Camp and regular campsite areas. Group camp looks tricky to turn around a large vehicle.

All 4X4 owners want a picture of their rig. It’s a thing.

More From Rolf Luetcke in St. David, Arizona

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting as much at this site. Instead, consider following me on Instagram, from your smartphone or desktop.

Handle: tgfarley

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do than blog posts. Thanks!


Hi Tom,

I had said I would send a photo of one I was taking and a little story.

The Ludlockite is a piece I had only read about in a big “Worlds Best Minerals Book we have. It was a piece that a mineral dealer had seen on a porch of a guy in Namibia that sold specimens from the Tsumeb Mine, one of the most famous mines in the world.

The piece on the porch was being used to hold open the screen door. The dealer asked if it was for sale. The guy sold it to him and he sent it right off to his US business and it turned out to be a new mineral and that one chunk on the guy’s porch was all there was.

I had no idea when I saw one for sale for $10, the piece I took the photo of, that it had been discovered in the mine after that first piece was studied. They traced the associated minerals with it and found the place in the mine it had come from.

More was brought out but it was never very common. I got this one for so little and am very happy with it, as much for the story as the piece and as pretty as it is.

The other two I took photos of today too. The Ludjibaite is a rare species and I paid a bit more for the piece, $45 but it is very nice.

The last one of Ludlamite from Mexico we got many years ago and I paid only $10 for it as well and it is a well crystalized piece.

So, that is my recent material.

Now to post them on Mindat.org

Later,

Rolf (Sunshine Gallery and Gifts, St. David, Arizona — S of Tucson)

Ludjibaite with Pseudomalachite 4mm fov Shituro, Katanga Prov. D. R. Congo (Blue)

Ludlamite 7mm fov Santa Eulalia, Chihuahua, Mexico (Green)

Ludlockite, Germanite, plus 5mm fov Tsumeb Mine, Namibia (Red)

More on the famous Tsumeb mine comes from this text at Mr. Kerry Day’s excellent website, he being the owner and proprietor of KAYGEEDEE MINERALS, a Canadian vendorship devoted to the mineral collecting hobby. He was an economic geologist/mineralogist/SEM-EDS operator for many years. “Selling off my vast collection of mineral specimens, gemstones and lapidary rough has become my retirement hobby.”

It’s a truly fascinating site that I recommend you visit immediately, for a sensational trip around the world while staying right at home. Thousands of great pictures.

http://kaygeedeeminerals.com/home_pagecanadian_minerals

TSUMEB MINERALS – Last updated April 12, 2019

The Tsumcorp polymetallic ore deposit was a near vertical ore pipe located near the town of Tsumeb, Namibia. A unique feature was three oxidation zones at various depths – the result of groundwater flow. The combination of oxidation(s) and unique chemistry created a vast suite of well crystallized minerals that are treasured by collectors worldwide. Unfortunately, mining ceased in the 1990s but neighboring ore pipes are now being explored/mined.

Bryan Smalley and Hidden Treasure Trading Company in Goldfield, Nevada

PLEASE NOTE:

As my August 1, 2019 book deadline draws near, I will not be posting as much at this site. Instead, consider following me on Instagram, from your smartphone or desktop.

https://www.instagram.com/tgfarley/

My Instagram account is fun and easier for me to do than blog posts. Thanks!


I visited Goldfield, Nevada twice this past week, stopping in each time to check on Bryan Smalley’s Hidden Treasure Trading Company. Byran continues to do fine things in Goldfield.

Bryan runs one of the Southwest’s most interesting rock and gift shops. His rock shop complex encompasses three buildings; don’t leave until you look into all three. Bryan carries jewelry, much of it local, much made by himself, maps, books, cabs and slabs, and some rough.

Check out this wonderful jasper he is now cutting. He has hundreds of pounds more.

Hidden Treasures Trading Company
489 Bellevue Avenue
P.O. Box 512
Goldfield, NV 89013
775-485-3761
775-485-3485

Bryan is expert on local rockhounding and accomplished at lapidary. He does knapping and can talk authoritatively on making flintlock strikers from locally collected chalcedony. Need advice on polishing? He has it.

Ask locals where Bryan is if you can’t find him. Try the Dinky Diner. Goldfield citizens won’t mind you asking, in fact, they are very friendly. You should give a wave to people as you drive by. Don’t get discouraged if you can’t find his shops at first. Drive around. You’ll enjoy your time.

Bryan has a minimal web presence but he is busy with real life, finding rocks, cutting rocks, and making jewelry. When investigating the nearby Gemfield Gem claims, make plans to see him. Well worth the effort.

bsmalleyhiddentreasure@gmail.com

Yes, he made that door himself. And the shop.

Another Update on The Gemfield Gem Claims in Goldfield, Nevada

Sharon Artlip has been in touch. She and her sister Nadiah Beekum own the Gemfield Gem claims in Goldfield, Nevada.

I’ve written quite a bit about the claims at this site and also in the May, 2016 issue of Rock&Gem Magazine. Another name for the claims now seems to be “The Rainbow Chalcedony Claims.”

Sharon writes that, “It has been a wonderful couple of years.  We are still having fun at Gemfield and always trying to improve it.  If you would like I will send you the current brochure.”

Rocks go for a dollar a pound. Everything is on the honor system. Register at one of several Goldfield businesses before going to the claim. Easy dirt road but not recommended for large RVs.

Wild burro country. Antelope, too.

Here’s a link below to the current brochure in .pdf:

2019-03-Gemfield Gem-Claims-History-pamphlet

This is a link to Sharon’s website supporting the claims:

http://www.gemfieldnv.com

And here’s a postcard photo of the claims. Click here or on the image for a much bigger view:

 

Sharon holding chalcedony in Goldfield, Nevada. She’s at Bryan Smalley’s Hidden Treasure Trading Company at 489 Bellevue Avenue.  Notice her truck’s new personalized license plates.

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.

Rolf

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

The Drill

The Drill. Checking my recent road trip finds with my Geiger counter, handheld metal detector, and my two UV lamps. Just to see if anything else is going on besides the reasons I originally picked them up.

One piece under shortwave fluoresces a nice green. May have found some common opal. This was on my last stop, when I pulled off the highway on a whim to walk the desert floor. At first I thought it was an agate because one side displays a translucent quality along with a wavy banding. When I got home, though, with my tools, I remembered I had seen something like it.

That piece matches the color, luster and the fluorescence of Arizona opal I recently got in trade from rock and mineral dealer Rolf Luetcke. Although simply white, the rock comes alive under shortwave UV. Not the intensity or brightness of Rolf’s piece, that material is top-notch, but the exact same color under the lamp.

Update: Not opal. A steel nail doesn’t scratch it, but a nail scratches the opal Rolf supplied. The piece must be chalcedony or agate, or whatever you want to call cryptocrystalline quartz. Hmm. What are the odds that I would find something that looks exactly like something else and fluoresces just like it as well. At least I know a place to search for fluorescent agates. The agates I have don’t fluoresce, certainly nothing green.

The Ernst Quarries Near Shark Tooth Hill, Bakersfield, California

Rob Ernst explains large concretions at a one-of-a-kind fee dig in Southern California. These large specimens are retained for education and scientific research, however, one can keep nearly anything dug up in a designated area.

For a limited time each year, the Ernst Quarries near Bakersfield opens much of their ground to the public to collect marine fossils. Shark teeth are the big draw. Rob will patiently and enthusiastically explain the ocean environment that was present 150 million years ago. Tiny to small shark teeth are everywhere, they can even be found on the surface. Digging and screening with persistence will reveal bigger teeth on most days.

I got to the Quarries on a day threatening rain. Weather can knock out a dig day when the final stretch of quarry road becomes impassable. Depending on conditions, Rob may arrange for people to walk a few hundred yards from their cars to the dig sites, rather than cancel a date.  Rob is keenly aware that people from as far as back East make flight plans, car rentals, and hotel reservations to get to his property. He does everything he can to make dig days happen.

Visitors can help by reading the information packet sent to them by e-mail and by  printing out the location  map and release form ahead of time. As of right now, there is a road repair project happening on Round Mountain Road with traffic control in effect. In leaving the property, wait for a pilot vehicle before turning onto the road, otherwise, you may wind up facing a line of traffic coming directly at you in the opposite direction.

The image below show a tooth in matrix, the species I do not know. I think this looks better than a tooth alone. Be careful in digging. The silt will now have to be stabilized first, perhaps with a diluted solution of Elmer’s white glue and water.  Rob can explain how to do this.

I knew nothing about marine fossils when I went and my trip opened my eyes into another world of collecting. Fossil collectors are as rabid as rockhounds are about their pursuit. If you are lucky and put in the hours, you might have a chance at finding something like the tooth below. This dig is highly recommended and I wish you luck if you go.

The shark teeth pictured below were gathered by surface collecting over no more than fifteen minutes of off and on looking. The white teeth and fragments show  bleaching caused by lying on top of the ground. The teeth with more color were pulled from the ground as these show indications on the surface of where some teeth are. I’d say your chances of finding something better over a period of a few hours of actual digging and screening are pretty good. Note the nice little one in the shadow.

Make sure to look for other things. Jeff spotted these two vertebrae pieces lying on the ground of a trench. Although identification is often impossible for vertebrae of this period, he thinks they may be from a junior whale or a sea lion. Perhaps. He also says that upon close examination of fossils like these, most show tooth marks, evidence of the food chain in action from long ago. Few things died a natural death of old age.