WOLF CREEK PASS: COLLECTING MORDENITE AND HAULIN' CHICKENS

 

Me and Earl was haulin' chickens
On the flatbed out of Wiggins 
And we'd spent all night on the uphill side                                                                                                               
Of 37 miles of hell called Wolf Creek Pass
Which is up on the Great Divide

At one time, way back in the 1960s and 1970s, it seemed like the “whole world, or at least most of the U.S., had heard of Wolf Creek Pass near Pagosa Springs, Colorado, “up on the Great Divide.” The song was recorded/performed by Bill Fries under his nome de guer  of C.W. McCall and was a parody of “truck driven music” and CB radio chatter. The song reached #40 on the  U.S. Pop Top 40 in 1975 and followed on the heels of McCall’s  first successful commercial hit song: Old home filler-up an' keep on a-truckin' café. In case you are wondering, Fries had a previous successful gig in the upper Plains and Midwest hawking Old Home Bread.

Now we spied a sign, says eat gas now
We decided to whip in and pick up some chow
At the old home filler-up an' keep on a-truckin' café

But McCalls best known for his mega hit song Convoy described as a “first-person trucker spoken monologue, backed by a country arrangement.” Whatever, the song reached #1 in both the Country Western and Pop Charts for several weeks and made C.W. McCall a household name and started the CB Radio craze that swept through and over North America. Every kid, and many adults (mostly male), had a “handle” (CB Name) and practiced talking like nitwits: “Breaker breaker, one nine (meaning let me talk on CB channel 19).  Folks, we got us a fox in the henhouse” indicating someone had seen an unmarked law enforcement vehicle. The roadways were full of cars and vehicles with very tall radio antennas sprouting out of the back bumper.  It may seem rather simple but, you know, people were having fun and not worrying about tariffs, the destruction of National Parks, federal troops in the streets, or the Ukraine.

Breaker one-nine

This here’s the Rubber Duck

You got a copy on me Pig Pen, c’mon?

Mercy sakes alive, looks like we got us a convoy!

But, back to Wolf Creek Pass situated on one of the most scenic highways in the West, U.S 160 running from Walsenburg on the east side of the Colorado Front Range to Durango in the far southwest of the State. The scenery, geology, and historical sights along the 222 miles will fill your memory scrapbook. However, perhaps the best-known section of the road is from South Fork on the east over Wolf Creel Pass to Pagosa Springs on the west.

Wolf Creek Pass is located in the San Juan Mountains of southwestern Colorado, an area famous for voluminous mid-Tertiary volcanism. Geologists working for the USGS have written a number of scientific reports on the area based upon detailed mapping and skillful laboratory analyses of the rocks. They have mapped at least 22 major ignimbrite sheets and associated caldera structures active between 34 and 23 Ma. The scientists at USGS have described the volcanism as characterized by explosive ash flow eruptions resulting in collapse and the formation of calderas. Many of these calderas are associated with large scale ore deposits such as the Creede Caldera Complex. Probably the largest caldera, and perhaps the best known (at least to geologists) feature, is the massive La Garita Caldera formed when a “really large” supervolcano blew its stack and spewed out a guesstimate of 1,200 cubic miles of the Fish Creek Tuff  over at least 11,000 sq. miles around 28 Ma. The caldera itself is a oblong structure ~25 x ~50 miles in size.

I remain uncertain about the exact age of the volcanics at Wolf Creek Pass and their relationship to an extrusive caldera. The rocks are reasonably close to the Platoro Caldera near Summitville where the ejecta is generally referred to as the Treasure Mountain tuff; however, I cannot find evidence that the tuff extended to the Wolf Creek area. Perhaps the tuff is related to the La Garita eruption? Unfortunately, since moving to rural Wisconsin I do not have the resources of geology maps commonly found in Colorado research libraries.

Arnold Hampson wrote the definitive rockhound paper on Wolf Creek Pass collectable minerals and stated the host rock in the region is the Conejos Quartz Latite. However, over the past twenty years terminology has changed, and the Conejos is now listed as the Conejos Formation and is related to eruptions of the Platoro Caldera around 30 Ma. So, I am still confused about specifics and will place a call to the Acme Building looking for Guy Noir, Private Eye, to help answer one of life’s persistent questions (thanks to Garrison Keilor).

Treasure Falls, 105 feet of sheer beauty. Public Domain photo courtesy of Ahodges7.

The small number of samples in my collection came from near Treasure Falls, a 105-foot gorgeous stream of water tumbling through and over the volcanics and situated along U.S. 160 about 15 miles east of Pagosa Springs—over the crest of Wolf Creek Pass heading west. The Falls are a popular visiting site for travelers and therefore parking is at a premium for RVs and almost every time I motored over the Pass I was unable to park my bumper pull RV and missed out on collecting. However, there was one instance when I was able to pull over and scurry to pound on the rocks a couple of times. The best collecting site is about ¾ of a mile north of the Falls in exposures along the roadway.

MinDat lists 11 valid minerals and 12 other varietal mineral names that have been extracted from the four small collecting localities referred to as Wolf Creek Pass. Most of the attractive collected minerals are zeolites, and mordenite [(Na₂,Ca,K₂)₄(Al₈Si₄₀)O₉₆ · 28H₂O] is the most abundant and spectacular of the group. The mineral occurs as thin, white tufts and sprays of delicate acicular crystals that are silky to vitreous, and transparent to translucent. They are usually associated with amygdaloidal cavities in basalt where it commonly is “associated with black nontronite, green celadonite, and orange heulandite” (Hampson, 2004). Interestingly, Hanner (1976) described the Treasure Falls mordenite crystals as “some of the finest in North America.”

Width FOV ~12 mm.

Width of spray ~1.5 mm.

Width FOV ~5 mm.

Above photomicrographs of acicular mordenite sprays on dark green/black nontronite. The patch of green “spherules” to the right on lower is perhaps celadonite or, perhaps an unknown/listed copper mineral?  The orangish base of some sprays may be due to heulandite-Na.

Nontronite [Na_0.3Fe₂((Si,Al)₄O₁₀)(OH)₂ · nH₂O] is also a common mineral in the Wolf Creek basalts but is not a zeolite. It is the ferric iron-rich end member of the Smectite Group of clay minerals. It commonly mixes with celadonite to form dark green to dark brown aggregates in the basalt vugs. At other times it occurs as almost black (?darkest green) spheric aggregates. It is quite soft at ~2.0 Mohs and the aggregates are waxy to resinous and appear opaque. Their color and size make my photography difficult. Inherently, most specimens of nontronite at other localities are much lighter in color---yellow green, yellow orange, brown, and green.

Vug filled with black nontronite with a narrow “rind” of celadonite and a few acicular crystals of mordenite. Maximum length of vug ~2 mm.

The upper photomicrograph is a small (length ~15 mm), vug-filling, “concretion-like” specimen that “popped out” of the vesicle and was damaged on both ends. The inside the “concretion” is filled with spherical aggregates of darkest green nontronite. A second unknown appears as a silver colored, metallic luster mineral (see lower photo). The reflection from the light source is intense. My only guess is pyrite.

Another somewhat uncommon mineral, at least in Colorado, is the Mica Group mineral celadonite [K(MgFe³⁺◻)(Si₄O₁₀)(OH)₂}. In the Wolf Creek basalts it often mixes with nontronite as described above. At other times it is composed of waxy, dull, blue-green to olive green spherules lining the vugs. Black nontronite spheres and acicular mordenite crystals are often associated with the lined cavities.

Vug filled with darker nontronite and celadonite with a greenish-gray patch of celadonite on top. Width vug .75 mm.

 

Vugs filled with celadonite. Large vug ~ 1 mm.

The tiny saponite crystals appear as dust-like flakes in mordenite-filled vug (width ~5 mm).

A surprise mineral, at least to me, is saponite Ca_0.25(Mg,Fe)₃((Si,Al)₄O₁₀)(OH)₂·nH₂O], an aluminosilicate member of the Smectite Group of clay minerals. Although  it occurs in many colors and habits (from small subhedral crystals to massive to granular and points in-between), the specimens from Wolf Creek are quite tiny, greenish-brown, subhedral to “flakes” and difficult to photograph details with my equipment. But interestingly, at Wolf Creek the minute saponite crystals are suspended from the acicular mordenite crystals.

REFERENCES CITED

Hampson, A.G., 2004, Zeolites and associated minerals of the Wolf Creek Pass area: Rocks & Minerals, vol. 79. No. 5.

Hanner, M. E., 1976, Mordenite at Wolf Creek Pass: Mineralogical Record, vol. 7, no. 6.

Went down and around and around and down
We run outta ground at the edge of town
Bashed into the side of a feed store
In downtown Pagosa Springs

THREE NEW MINERALS FROM NEW MEXICO: RAY, VIRGIL & STUART

 

I was perusing articles from www.earth.com and ran across great news for RMFMS rockhounds. Geologists have discovered three new minerals from Cookes Peak in Luna County, New Mexico. According to MinDat.org “Cookes Peak is a 2,563 m (8,408 ft) high granodiorite mountain peak located approximately 27 km (17 miles) N of the city of Deming. Cookes Peak Mining District is a lead-zinc-silver mining district that produced about $4.2 million worth of ore between 1876 and 1965 from carbonate replacements and veins… Economic mineral deposits in the Cookes Range include galena (lead), sphalerite (zinc), silver, copper, gold, manganese, and fluorite.” However, the ore-depositing hydrothermal solutions also left behind oxidized cavities containing rare molybdic acid hydrate minerals: raydemarkite MoO₃-H₂O (Triclinic lattice); virgilluethite MoO₃-H₂O (Monoclinic sheet structure); and stunorthropite {NH₄}₄[Mo₂O₆(MoO₄)₂]. Now, I don’t even pretend to understand anything about the hydrated forms of molybdenum trioxide; however, I understand the origins of the mineral names. And these origins should excite rockhounds.

Ray DeMark seems to have spent several lifetimes exploring and collecting minerals from New Mexico but is best known as the claim owner of the Blanchard Mine who is always willing to lead rock/mineral clubs on a collecting foray. The Blanchard Mine, part of the Hansonberg Mining District, is located in the Rio Grande Rift Zone southeast of Socorro. Every collector who has followed Ray into the mine area has come away with a collecting bag stuffed with fluorite, galena, barite, brochantite, and others, including linerite (if lucky). The Mine is best known for specimens of electric blue fluorite (Bingham Blue), and for Ray DeMark and his unlimited generosity of sharing with rockhounds.

Virgilluethite was named for Dr. Virgil W. Lueth, emeritus senior mineralogist/economic geologist from the New Mexico Bureau of Geology.  Rockhounds and mineralogists will recognize Virgil as the former director of the Bureau’s Mineral Museum from 1994 to 2022 and his leadership in the Museum’s premiere annual event, the New Mexico Mineral Symposium. The Symposium is unique in that it provides a forum for both professionals and amateurs to share information and knowledge of mineral occurrences. During Virgil’s tenure with the Symposium, he seemed to be everywhere greeting visitors, showing off the collections, and making certain the coffee arrived on time. The 45^th Symposium will be held on November 7-9, 2025.

Stunorthropite was named for Dr. Stuart A. Northrop (1904–1994), a professor of geology at the University of New Mexico from 1928 to 1969. He is the author of Minerals of New Mexico, the most comprehensive work on the state’s mineralogy. First published in 1944, it has undergone several major revisions and is currently in its third edition. In 2016 the Department of Earth and Planetary Sciences at the University of New Mexico launched the initial Dr. Stuart A. Northrop Distinguished Lecture Series noting contributions to the UNM Department of Geology during his long tenure as Chairman (1929-1961) were profound. He laid the foundation of the present department, including the creation of the MS and PhD programs and the construction of the department's building, which now bears his name.

So, there it is—three new minerals from New Mexico honoring three of the best known RMFMS rockhounds/geologists from the Land of Enchantment.  Fantastic photos of the three new minerals may be seen at https://www.nmt.edu/news/2025/new-minerals.php.   

WHAT DO YOU KNOW ABOUT ANTIMONY?

 

Two small items have triggered this report: 1) I belong to the Baltimore Mineral Club and at our last meeting we talked (by ZOOM) about the element antimony and the mineral stibnite; and 2) a former student of mine, now living in Alaska, told me that the June 5^th edition of dermoitcole.com/reporting from Alaska/ had a story about trucking antimony ore from Alaska to a smelter in Montana. Sure enough, the story stated there is a “push to mine antimony in the Fairbanks area, as well as in Tok and off the Denali Highway. With export restrictions by China, the price of antimony has soared in the past year from $13,000 a ton to ~$50,000 per ton. U.S. Antimony says it’s looking to truck antimony ore some 2,000 miles from Alaska to its processing plant in Montana. That operation could start as soon as September.”

Wow, that’s interesting. So, where does the U.S. currently mine stibnite, the major ore of antimony?  It seems that at the present time there are no antimony-producing mines in the U.S.  That little tidbit led me to another story in Forbes.com about the fact that without antimony produced here in the United States, the outcome of World War II might have turned out differently. Read on.

No, really, it could have. Antimony is a strategic critical mineral that is used in all manner of military applications, including the manufacture of armor piercing bullets, night vision goggles, infrared sensors, precision optics, laser sighting, explosive formulations, hardened lead for bullets and shrapnel, ammunition primers, tracer ammunition, nuclear weapons and production, tritium production, flares, military clothing, and communication equipment. It is the key element in the creation of tungsten steel and the hardening of lead bullets, two of its most crucial applications during WWII.

Prior to the buildup to the War, the United States was almost entirely dependent on China for its supply of antimony. When that supply was cut off by Japan, America had to find another source of this key mineral. Fortunately for the U.S. at that time, a gold mine in central Idaho called the Stibnite Mine was able to step up production of the antimony that is an element in the mine’s ore and helped fill the void.

The Stibnite mine ended up producing fully 90% of America’s demand for antimony for the duration of the War and was key to producing 40% of the tungsten steel needed for the military effort. Following the War, output from the Stibnite Mine gradually declined, and its operations were shut down entirely in 1997.

Interesting, eh? Read on from Metaltechnews.com.

So back to today’s world where United States Antimony owns and operates an antimony smelter in Montana – the only facility on American soil designed to upgrade raw antimony feedstock into antimony oxide used to make flame-resistant compounds for home and military use, antimony metal for bearings and artillery, and antimony trisulfide for ammunition. But as noted, the U.S. does not mine antimony. That means the Montana-based company is reliant on imports from Mexico and other countries for the raw materials to feed its smelter. So maybe Alaska does not seem so far away from Montana.

Today, the U.S. finds itself once again wholly reliant on other countries for its antimony needs, most heavily China and to a lesser extent, Russia (before the War in Ukraine). The global demand for antimony in the coming years cannot be met from current supplies. If true, this will impact all of us in a variety of ways, because antimony is a crucial element in far more than just military applications.

However, the News gets worse since at the end of last year China banned exports of antimony to the U.S. Considering that China controls roughly half of the global antimony production – Tajikistan and Russia account for another 30% of global supply – this ban leaves the U.S. with few options for this critical and strategic metalloid.

 

From Oilprice.com we learn that after China banned exports to the U.S. Prices had already doubled in the second half of 2024 since China said in August that companies would need to apply for export licenses to export antimony ore, metals, oxides, hydrides, and other related products. 

 

The ban reverberated through the supply chains and is raising costs for battery makers with expensive and difficult-to-find supply.  

In the global antimony market, China is not only the top producer, but also boasts the majority of antimony processing facilities, somewhat analogous to China’s role in REEs production, the U.S. Geological Survey says.

 

So, that led me to this story from USantimony.com. On March 17, 2025, a two-container international shipment of approximately fifty (50) tons of stibnite (antimony) ore, departed the port of loading in Melbourne, Australia, with the final destination and port of discharge to be at the Port of Manzanilla, Mexico for ultimate delivery to the United States Antimony Corporation ("the Company") Madero Smelter. The Company made partial payment on the value of the shipment’s invoice, equaling $715,413 USD, ahead of the actual time of departure as called for under the existing contract. Evergreen Shipping Agency (Australia) PTY Ltd., the shipping agency, routed the vessel through The Port of Ningbo-Zhoushan in China. The vessel’s actual time of arrival in Ningbo was April 14, 2025. All necessary payments and required paperwork were properly accounted for. Chinese Customs withheld these two containers carrying stibnite (antimony) ore for approximately eighty-two (82) days with no apparent reason provided to all parties involved

On June 23, 2025, the Company was informed that Chinese Customs finally agreed to release the containers on the condition that they be returned to their point of origin/loading dock in Australia. The Chinese Customs would not release the shipment to their intended final destination to the Port of Manzanillo for their final delivery location at the Company’s Madero Smelter. The Company can only assume this was either due to the contents being antimony ore, or the owner name, US Antimony Corporation, or possibly both. China previously announced, back in September of last year, a ban on all shipments of antimony ore and finished products originating from China and exported to any country in the world, including the United States.

 

Forbes.com has given us an interesting scenario: consider antimony’s  usage in the high-tech sector, where it is a key ingredient in semi-conductors, circuit boards, electric switches, fluorescent lighting, high quality clear glass and lithium-ion batteries. No antimony, no iPhones. No hi-definition TVs. No modern kitchen appliances, all of which make use of digital circuitry. Oh, and that car you’re thinking about buying? Sorry.

Now, consider this: There can be no “energy transition” without adequate supplies of antimony. That thick, heavy glass used in solar panels? It’s made with antimony. Those 300 to 700 foot-tall windmills that sporadically produce electricity? Made with antimony. Antimony is a key element in the manufacture of lithium-ion batteries, as mentioned above, but even more crucial is the fact that it is integral to the development of the next-generation liquid metal batteries that, as Ecclestone pointed out during the webinar, hold the key to truly scalable energy storage for wind and solar power.

It seems almost unbelievable that this country has allowed itself to become almost 100% dependent on imports of a metal integral to so many applications as antimony. Of course, the U.S. is also in a similar situation related to better-known critical minerals like lithium and cobalt, which are also key to the production of solar panels, wind turbines and lithium-ion batteries.

The last news that I could find is that United States Antimony Corporation (NYSE American: UAMY) is bringing antimony mining back to the U.S. The company recently announced that it has started buying land and mining claims near its old smelter in Thompson Falls, Montana. This move could help reduce America’s heavy dependence on foreign sources of antimony---when it finally starts production.

Above information in this article, compiled in mid-July, 2025, has been taken from various sources: Oilprice.com, Forbes.com, USGS.gov, North of 60 Mining News, Reuters.com, dermoitcole.com, usantimony.com. metaltechnews.com. Want to learn more? Get on a web browser and start hunting—there are hundreds of dependable (seemly) articles in corporate reports, government reports and articles, journals, newspapers, and you name it. Kind of scary!