I’m new to Arizona. I’ve grown up in and lived most of my life in Canada. That means the desert landscapes, flora, fauna and types of minerals (secondary minerals) of the South-West are all new to me! I’ve travelled much of the world but Arizona is one of THE most interesting, intriguing and satisfying environments that I have encountered (especially during winter and spring!).
Recently, I joined a field trip of the Tucson Gem and Mineral Society, destination; the Red Cloud Mine, north and east of Yuma, not far from the California and Arizona border. I left Tucson and travelled NW on I-10 to Highway 8 and then west on Highway 8 to Yuma for a stay overnight and ready to start early the next morning, heading up highway 95 towards the mine.
I had NO idea what collecting would be like. Actually, I didn’t care. It just seemed like a good idea to visit the Red Cloud Mine which is one of the premier mineral localities of the world. This year, 2019, was the year of the “Wulfenite is Loved” theme at the Tucson Gem and Mineral Show and visions of colourful, well-formed crystals of the AZ-ikonish, lead-molybdate were floating around in my brain. The trip to the mine was important and, if I happened to find some good crystals, that would be a bonus!
I think that I enjoyed the drive from Tucson to Yuma and then to the Red Cloud Mine just about as much as I enjoyed being AT the Red Cloud Mine! This “article” is really a photo-essay showing the road trip to the Red Cloud Mine, a little about the location, collecting and then some of the minerals that I returned with. I’ll show you some of the scenery, flora and minerals that I encountered. Didn’t encounter any fauna! I hope you enjoy it, as well!
About the Red Cloud Mine
The following information has been summarized from Arizona Lead and Zinc Deposits, Part II, Arizona Bureau of Mines, Geological Series No. 19, Bulletin # 158, kindly provided to me by Les Presmyk, an authority on the Red Cloud Mine and "all things Arizona", when it comes to mineral specimens. I’ve added my observations to the information gleaned from the reference.
The Red Cloud Mine was a fairly small mine, as modern mines go. It is located at 750 feet above sea level, near Yuma and the California border with Arizona. It was originally mined during the 1880s and over the years, developed to a depth of 500 feet or so via various shafts, winzes, raises, drifts and stopes. The remnant vein mineralization in the 1950s averaged about 6% lead and 10 troy ounces or so of silver per ton. There were no doubt higher grade sections of the veins, earlier, but few records are available.
The vein occurs in a fault zone and is composed mainly of “limonite”, hematite, quartz, fluorite and calcite. According to the Arizona Bureau of Mines (ABOM) report, there is considerable fault gouge and brecciated rock around the vein. I observed this in the surface exposure of the vein and expect that the underground workings were tricky due to difficult ground conditions. There are many open spaces in the vein material and the openings are often drusy quartz lined. When not filled with iron and manganese oxides the openings commonly contain fillings or crystals of wulfenite, willemite, cerussite, mimetite and calcite. According to the ABOM report, there also can be malachite, vanadinite, smithsonite. Small masses of galena can be found and, presumably in large masses, at times since argentiferous galena was the main ore mineral. Also according to the ABOM report, the galena can be associated with anglesite, cerussite and cerargyrite. As well, the report indicates that the lower workings contained more zinc mineralization than lead, all in secondary minerals. Odd, though. I didn’t see a trace of zinc mineralization during my limited visit.
I was surprised at the number of open spaces in the vein material and the quantity of small crystals of wulfenite, willemite, cerussite, mimetite and hemimorphite. I recognize that I was looking through vein material both in-situ and loose that is the “leavings” of several waves of professional collectors. Still, there are beautiful, small but macro wulfenite crystals to be found and oodles of micro crystals. Roger the resident collector, mentioned further, below, has found some beautiful large and significant crystals and specimens of wulfenite. He spends many hours exploring the workings and has learned where to look. He was very generous with his knowledge and guidance but we were probably not shown the best place to collect on surface and certainly we did not go underground. (I would have loved to!)
Figure 1) The first major landmark that I encountered as I headed north-west out of Tucson is Picacho Peak, the unique mountain, a third, or so, of the way from my winter home SE of Tucson to Phoenix. Here is a view of Picacho peak with a pecan tree grove in the foreground. We grow LOTS of pecans in Southern Arizona!
Figure 2) This is a view from Highway 8 or typical mountain scenery from a fairly nice Sonoran Desert valley.
Figure 3) Lots of Palo Verde trees and Saguaro cacti along the way.
Figure 4) And more!
Figure 5) If you get off Highway 8 more than a few feet, you’ll encounter these signs. Very close to the border with Mexico. The flowers in the front are “Orange Globe Mallow”.
Figure 6) One of the things that surprised me the most was the amount of agriculture that I encountered along the way. Many of the valleys were lush with green crops or rich with freshly plowed soil. That is the thing about the desert. Add water and nutrients and plants burst out of the ground. This is in the Dome Valley, just east of Yuma.
Figure 7) Here are more fields just north-east of Yuma on the way to the Red Cloud Mine Road. Note the irrigation canals? I believe they carry water tapped off of the Colorado River, just west of that location.
Figure 8) I saw many types of crops, including orchards, hay and others. Just add w
Figure 9) Sunset in Yuma. I don’t think palm trees are a native species but they are often seen in Arizona cities and towns.
Figure 10) Sunrise, just east of Yuma. I did start early in the morning, eager to get at those red wulfenite crystals and other interesting minerals at the Red Cloud Mine.
Figure 11) To get to the Red Cloud Mine Road, you head north on Highway 95 out of Yuma to Martinez Lake Road and, then turn left and head NW past the US Army Proving Grounds headquarters.
Figure 12) Then proceed to 10 miles to… the Red Cloud Mine Road! How easy is that? That is where the easy part stops. The road to the Mine is about 16 miles long. The first 6 miles or so is in good condition but it deteriorates into a fairly rough road. I have a two-wheel drive Trail Blazer that managed it just fine, though. You want good clearance.
Figure 13) The first part of the Road is in fairly heavily wooded large “washes”. Washes are dry riverbeds that, in some years, at certain times of the year, can be gently flowing streams or raging torrents depending on levels of rainfall and mountain snowpack. When they are dry, which is most of the time, they make dandy roads through the desert.
Figure 14) Another section of a “wash” - a dry river bed turned road.
Figure 15) Much of the Red Cloud Mine Road traverses pretty desolate, rocky desert, travelling along or cutting across numerous washes.
Figure 16) Pretty cool, though!
Figure 17) Highly weathered rocks!
Figure 18) Must be SOME water around, at times, for all of these plants and trees to grow!
Figure 19) Much of the road has these signs every thousand feet or so. The road travels through a significant portion of the Proving Grounds.
Figure 20) The road travels higher and higher and vegetation gets scarcer. Driving on this wash gravel is like driving on a couple of feet deep of marbles!
Figure 21) And drier!
Figure 22) Even in this harsh climate, beauty bursts forth in the spring. Here are some prickly pear and yellow brittle bush flowers.
Figure 23) A close up of that flowering prickly pear cactus.
Figure 24) Another nice, flowering prickly pear cactus and a couple of chollas.
Figure 25) The ocotillos are in leaf and blooming. Other-worldy!
Figure 26) Good looking rocks! Remnants of intrusive dykes?
Figure 27) Some of the terrain looks like piles of different coloured dirt but they are just highly weathered outcrops of different colored-types of rocks.
Figure 28) Tough place!
Figure 29) Here is an overview of the Red Cloud Mine. The pit is just to the right of those greenish buildings and behind the open shed. Sorry, the picture is a little fuzzy.
Figure 30) Made it!
Figure 31) A little good-natured disrespect. Ed Over was a legendary mineral collector and collected many fine wulfenite crystal specimens here, decades ago.
Figure 32) Here is the open pit that has, in relatively recent years, largely been excavated to search for wulfenite pockets. Note the open stope at the far end. I collected just below and beside it.
Figure 33) Here, Roger, the professional collector, miner and watchman shows off a larger wulfenite crystal he collected. He lives at the mine full time and comes into “town” every couple of weeks for supplies. He has a trailer, a well, 3000 gallon water tank and many of the comforts of home.
Figure 34) And another… I believe that he collects underground, as well as from certain spots on the pit wall. There are are a couple of other fellows that work with him at times.
Figure 35) Personally, I like ’em on matrix. Like this one! BTW, he doesn’t give’em away! This specimen would cost a large number of $. Actually, he will give you a small one. Roger spent his working life as a self-described “gyppo miner”, capable of all aspects of underground mining. Roger also has a degree in geology but never did worked in geology after he found he could make WAY more money as a miner. He considers himself retired now but his mining skills no doubt serve him well at the Red Cloud Mine. Roger says that he has not seen any visitor find large wulfenite crystals like the above crystals. I think that there are certain areas that these sorts of crystals can be found both above ground and underground and we were not made privy to that knowledge.
Results of Collecting
I was fortunate to find a number of wulfenite crystals, all small but, still, beautiful and classic Red Cloud Mine. They all have that red-orange colouration, sometimes more red and sometimes more orangey. As well, I also found lots of really nice willemite, all sharp micro crystals and all brilliantly fluorescent.
As well, I did find cavities of fluorite crystals. The fluorite crystals are not great crystals and mostly colourless but often serve as substrate for the more exotic minerals. The fluorite has nicely blue-purple fluorescence and adds to the intrigue of the rich willemite specimens. Similarly, there are lots of vugs lined with drusy quartz crystals that sparkle in the strong, ever-present Arizona sun. The quartz druses are often the base for the more rare minerals.
Additionally. I did find a couple of vugs with hemimorphite, mimetite and cerussite crystals. I expect that, if I spent more time at the mine and with the microscope, I’d find other well-formed crystals of various minerals.
Here are some photos of the minerals that I found:
Figure 36) Wulfenite crystals on quartz crystals. Some white opal. FOV 25mm across.
Figure 37) Sharp wulfenite crystals in quartz and calcite vug. FOV 25mm across.
Figure 38) A 4mm wulfenite crystal showing some pyramidal growth features.
Figure 39) Nice wulfenite crystal, 4.5 mm across.
Figure 40) Wulfenite crystals, largest crystal 9mm.
Figure 44) Willemite crystals as more defined, hexagonal prisms, 1mm long.
Figure 45) Willemite crystals, 1mm long. Larger crystal to the right.
Figure 46) Red Cloud Fluorescents: Greenish-willemite, red-purple-fluorite.
Figure 47) Fluorescent photo of the Figure 42 willemite crystals.
ALL of the Willemite fluoresces a bright green colour like in Figure 46. For some reason, I could not capture that colour through the microscope. All of the micro Willemite photos show the mineral with a ghostly whitish glow.
Figure 48) Mimetite, a 1mm cluster of very tiny hexagonal, terminated crystals.
Figure 49) Hemimorphite crystals, up to 1mm long.
Other Specimens
Here are some REAL wulfenite crystals and specimens:
Figure 50) Wulfenite from the collection of Ray McDougall. Lustrous, red-orange crystals. Specimen is 12.8cm across. R. McDougall photo.
Figure 51) “Perfect”, gemmy, wulfenite crystal on quartz-calcite matrix. Specimen is 25mm across and is now in the collection of Jeane Jaramillo. R. McDougall photo.
Figure 52) Excellent, three dimensional cluster of wulfenite crystals, 10.5cm across. University of Arizona Gem and Mineral Museum specimen.
Figure 53) Wulfenite, Red Cloud Mine, 10.5cm across. University of Arizona Museum Specimen LF 554, on loan from Mark LeFont.
Figure 54) Wulfenite, Red Cloud Mine, 15.0cm across. University of Arizona Gem and Mineral Museum Specimen.
Summary
I was delighted to visit the Red Cloud Mine after knowing about it all of my life and after having sold a number of nice specimens over the years. Hopefully, I’ll return there sometime in the future and undertake another attempt to find a larger cavity with some larger, beautiful crystals in it than I found the first time! In the meantime, I hope that you enjoyed the trip to the Red Cloud Mine as much as I did.
Acknowledgements
Thanks to Roger, at the Red Cloud Mine, for his guidance during the visit. I hope that he continues to find great crystals.
Thank you to Les Presmyk for the knowledge that he shared about the mine.
And thank you to Ray McDougall for the use of his photographs.
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