LEARNING FROM ANTIMONY MINERALS

I AM STILL LEARNING      Michelangelo at age 87

I AM STILL LEARNING      Mike today

Antimony is one of those minerals that tends to ring a bell with people, but very few really know what it is, where it comes from, or how it is used!  Actually, antimony has been known for centuries and was being used as an eye cosmetic (mascara) by 3000 BC., and the most famous advocate might have been Jezebel whose exploits are recorded in the Hebrew Bible.  In her last earthly event before she was killed, Jezebel  “painted her face, and tired her head, and looked out at a window.” (2 Kings 9:30).   Early uses as a “medicine” evidently were for laxatives; however, antimony can be toxic and I would “prescribe” ExLax rather than powered antimony!  Today physicians may prescribe a form of antimony to “kill” nasty protozoans that have infested a person. Antimony is used widely in industry, mostly as a hardener in the manufacture of lead-acid batteries and ammunition (~40%).  It is also widely used in clothing as a fire retardant (~40%), glass, paint, and PET (polyethylene terephthalate) plastic bottles (PET beverage/water bottles should never be hearted) account for most of the remainder.  With our “throw away” culture all of those PET bottles containing antimony head to the landfill and may end up emitting toxic fumes (long term studies are inconclusive).

China is the world’s leading producer of antimony and in 2019 their mine production totaled 100,000 metric tons (out of 169,000 metric tons produced world-wide).  The other major producers were Russia, Tajikistan, Bolivia, and Turkey---countries not known for sterling environmental records. The United States has not mined antimony for several years; however, there are known reserves in Nevada, Utah, Idaho, Alaska, and Montana.  About 14% of our domestic use is obtained from recycling lead-acid batteries while the remainder (86%) is imported.  In 2018 antimony was added to the National Defense Stockpile of minerals. (Information above from U.S. Geological Survey, Mineral Commodity Summaries, January 2020).  

Stibnite, antimony sulfide [Sb₂S₃] is the major ore of antimony although some 200 or so other minerals contain the element.  A Posting describing stibnite may be found April 16, 2013.

I have a few of these “other” minerals containing antimony in my collection and four were described in past postings including cylindrite (January 23, 2017), cervantite (April 16, 2013), franckeite (February 26, 2020), and native antimony (April 16, 2013).  Four others, in my collection described below, include meneghinite, senarmontite, stibarsen, and gudmundite.

Senarmontite is an antimony oxide [Sb₂O₃] that often appears as nice octahedral crystals that at first glance could be confused with the octahedrons of magnetite.  However, senarmontite is not magnetic and has a color of gray to white or occasionally red to colorless.  The colorless variety is transparent while the others are translucent to mildly opaque.  Although my specimen is a nice octahedron, senarmontite also occurs as a massive and or granular mineral. Colorless crystals are subvitreous while others have a resinous luster, but all have a white streak.  The mineral also is quite soft at ~2 or a little more (Mohs).

The octahedron of translucent senarmontite.  Width/length crystal ~7 mm.     

My specimen is from the Djebel Hammimat Mine, Ain Babouche District, Oum el Bouaghi Province, Algeria, and I was unable to learn much about the mine except that it produced antimony from a variety of minerals including senarmontite. MinDat noted that senarmontite is a secondary mineral formed by oxidation of antimony, stibnite, and other antimony minerals in hydrothermal antimony-bearing deposits.

Stibarsen (AsSb) is a rather interesting mineral for several reasons.  The name comes from its composition of stibium (Latin name for antimony) and arsenic. It is one of those minerals that is composed of two metallic or semi-metallic elements (alloy-like).  In most minerals, metals or semi-metals form a positive charged cation (+), for example cuprite (copper oxide, Cu₂O).  However, I have posted on several Arsenide Group minerals where the arsenic serves as the negatively charged anion (always 3-) and combines with the positive metal cation: algodonite Cu₆As; domeykite Cu₃As; löllingite FeAs₂; skutterudite (Co,Ni)As₃. There are also similar Antimonide Group minerals where antimony serves as the negative charged anion (always 3-).  They are much rarer than arsenides and the only specimen in my collection is the silver antimonide dyscrasite Ag₃Sb.

MinDat refers to stibarsen as an antimonide with a formula of AsSb with both the antimony and arsenic having oxidation states of 3-(As) and 3- (Sb).  However, the ratio of arsenic and antimony seems to vary and other databases such as WebMineral use SbAs.  Then there is the discredited mineral allemonite floating around in the literature.  Actually, it was designated a synonym of stibarsen in 1982 when the IBM anointed stibarsen as the correct name.  However, readers might encounter allemonite as a descriptive term: allemonite I—greater content of antimony than arsenic; allemonite II—equal content of arsenic and antimony; allemonite III---greater content of arsenic than antimony.  And, so it goes.

The beautiful thing about learning is that nobody can take it away from you.  B.B. King

Stibarsen has a tin-white to gray to gray-white metallic luster and color with a gray-black streak.  It occurs as massive or a reniform (kidney-like) habit (often seen in hematite).  As a metal it is opaque and fairly soft at ~3-4.  It seems to form in lamellar, graphite-like sheets, is brittle and tarnishes to a dark gray.  As with arsenic, stibarsen puts out a garlic-like odor when struck. Stibarsen occurs in pegmatites and hydrothermal veins.

The graphite-like sheets of stibarsen.  Width FOV ~1.1 cm.

Reverse of above photomicrograph.  Lustrous, botryoidal typical stibarsen.  Width FOV ~1.1 cm.

My specimen, as do many stibarsen specimens on the market, came from the Engineer Gold Mine, Tagish Lake, Atlin Mining Division, British Columbia, Canada. The Mine and the District are well known for crystalized gold specimens and a “gold rush” to the area was contemporaneous with the more famous Klondike Gold Rush.  There is still exploration activity at the mine and an excellent summary of past mining and current work may be found at :  www.davidkjoyceminerals.com/pagefiles/articles_engineermine.asp

Gudmundite is an iron antimony sulfide, FeSbS, that has been collected from a number of localities but is best known in the mines of Bolivia and Slovakia.  I find it interesting that the iron arsenic sulfide, arsenopyrite (FeAsS), is a very common hypogene mineral, the oxidation of which accounts for a large portion of the arsenic found in secondary minerals, especially as the AsO₄ radical while gudmuntite is not a common mineral. Gudmondite, like other antimony minerals, has a metallic luster and a steel-gray to silver white color and will tarnish with exposure to “air.”.  It usually appears as a fine-grained crystalline mass with the crystals beyond the power of my scope.  It is opaque and will leave a gray black streak on unglazed porcelain. It is harder than stibarsen with ~5-6 (Mohs). 

Grainy, metallic gray crystals of gudmundite.  Width FOV ~1.6 cm.

My specimen of gudmundite came from the Pezinok Antimony Mine in the Male Karpaty Mountains, Slovakia. MinDat states “the mine is one of the largest hydrothermal antimony deposits in Slovakia. Small-scale mining of antimony started in 1790 and after some breaks finally stopped in 1991 for economic reasons.”  Many of the mines in the region also produced gold and electrum.  I cannot read Slovak nor Czech (the language of most of the professional articles) but Dill (1998 in English) noted that antimony mineralization in the Western Carpathian Mountains (i.e. Pezinok Mine) occurs in tectonic collision zones but unlike porphyry copper deposits, antimony deposits are distal relative to the subduction zone. They are confined to sections of the fold belt where the continental crust is thick and was subject to strong horizontal displacements. I found that one of life’s persistent questions and will continue reading!  

At last, an antimony mineral with an identifiable shape, and one collected from the U.S.—meneghinite, a lead copper antimony sulfide [Pb₁₃CuSb₇S₂₄] from the Red Bird Mine, Antelope Springs Mining District, Pershing County, Nevada—15 miles or so east of Lovelock.. The Red Bird was primarily a mercury mine and is well known for beautiful red crystals of the mercury sulfide, cinnabar (see Posting November 30, 2012). Secondary production included gold, silver, copper, lead, and antimony. According to the USGS (https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10040308) The Red Bird was discovered in 1907 but did not produce until 1914 and then intermittingly after that until closing shop in 1949.  The disseminated cinnabar was hosted in Mesozoic (Triassic and Jurassic) carbonates, especially in fracture zones. Evidently these veins were emplaced during the Miocene as a result of extensional magmatism (Noble and others, 1988).  That is, Miocene extensional tectonics involved the stretching of the earth’s crust producing what we know today as the Basin and Range physiographic province.

Prismatic, metallic crystals of meneghinite, stacked in mass.  Width FOV ~1.2 cm.

Above two photomicrographs of meneghinite in and on a quartz matrix.  Width FOV 1.2 cm. 

Meneghinite has the metallic luster and blackish-gray or lead-gray color of other lead and antimony minerals.  It often occurs, as in my specimen, as striated acicular or prismatic crystals (long and slender) that are quite brittle.  The mineral is opaque, leaves a shining metallic black streak, and is quite soft (~2.5 Mohs). As noted above, it occurs in hydrothermal veins associated with many other metallic minerals. At some localities, bismuth may replace some of the antimony and copper content is variable.  About the only way I could visually identify meneghinite (maybe) is to know about the collecting mine!

Learning is a treasure that will follow its owner everywhere. Chinese Proverb

 REFERENCES CITED

Dill, H., 1998, Evolution of Sb mineralisation in modern fold belts: a comparison of the Sb mineralisation in the Central Andes (Bolivia) and the Western Carpathians (Slovakia): Mineralium Deposita. Vol. 33.

Noble, D.C., J.K. McCormack, E.H McKee, M.L. Silberman, and A.B. Wallace, A.B., 1988, Time of Mineralization in the Evolution of the McDermitt Caldera Complex, Nevada-Oregon, and the Relation of Middle Miocene Mineralization in the Northern Great Basin to Coeval Regional Basaltic Magmatic Activity: Economic Geology, v. 83.

ALUM MINERALS, ELEGANT TROGANS, AND SHAVING CUTS

An Elegant Trogan.  Photo Public Domain and courtesy of Dominic Sherony.

My previous posting was on the mineral halotrichite, a hydrated iron sulfate with long wispy crystals or tuffs as a common habit.  I also, several years ago, purchased a mineral box containing halotrichite crystals.  I remember the specimen cost a buck and was covered with a thick layer of dust so I brought it home but dare not blow away too much dust as the crystals were mostly loose and on the surface of an unknown matrix.  But in this time of self-quarantine I have been taking a second peek at many of the mineral specimens stored in the drawers.  So, out popped this specimen labeled: Halotrichite, Karshaw (sic. Harshaw) District, Chief Mine, Coll. 1971, FitsHue Collection. I knew about the Harshaw Mining District mainly due to the Japan Law quartz crystals collected from Washington Camp mining area.  In fact, the entire Patagonia and neighboring Santa Rita Mountains are checked full of old mines and prospecting holes.  I also have camped at Patagonia Lake State Park with two memories of the area: 1) I spotted my first and only specimen of the Elegant Trogan [Trogon elegans]; and 2) in asking directions to the Washington Camp I was warned by locals not to drive there alone, and to travel armed.  It appeared that drug smugglers were in the area.  So, I switched from minerals to bird watching and especially was interested in the Trogan since the Audubon Guide to North American Birds noted “Since the 1890s the possibility of seeing a trogon has lured birdwatchers to southern Arizona. With its brilliant metallic colors and odd croaking call, the Elegant Trogon brings an exotic touch to the wooded canyons and streamside sycamores where it lives. The observer who finds one may get to watch it at leisure: rather sluggish, the trogon may sit upright on one perch for several minutes.”  Trogans are tropical birds but a few migrate north to breed (April-September) in the sycamore canyons of extreme southern Arizona, especially in the Patagonia, Huachuca (Ramsey Canyon) and Santa Rita Mountains (Madera Canyon).  They are sort of a Holy Grail to dedicated bird watchers.  I was honored to be a chosen one and stand under a tree and observe and chat with the fellow for 10 minutes until I quietly departed.  It certainly was the highlight of my meager birding career.


OK, back to the halotrichite, which really doesn’t look like halotrichite--at least to me.  According to MinDat halotrichite is not known from the Chief Mine although Anthony and others (1993) noted its presence. The polymetallic (but mostly copper) Chief Mine is located as one of a group of 12 claims crowded together in Alum Canyon.  It was a small mine and evidently has not been active in the last 100 years or so; no production records were located.  Its next-door neighbor, the World’s Fair Mine, also was in Alum Canyon and was a much larger producer (copper) and MinDat lists 56 valid minerals known from the Mine, including an isolated nodular specimen of halotrichite.  However, there are other photos in MinDat of what is described as Alum Group minerals, a generic name for hydrated aluminum alkalic metal sulfate [XAl(SO₄)₂-12H₂O]. A “dead ringer” photo in MinDat was a “white fibrous alum group mineral collected by Rolf Luetcke at a small tunnel off Alum Gulch”


Most of the mining in the Harshaw District is from copper minerals disseminated in a Tertiary rhyolite and/or lodes/veins of ore along fault fissures and breccia zones in limestones.  What is really interesting is a statement by Schrader and others (1915): “In Alum Canyon, on the southwest, the weathered surface of the rock and the alluvial gravels derived from it are coated with efflorescence and incrustations of alum, some of whose constituents seem to be derived from the pyritic content of the rock through oxidation.” This description would seem to indicate the alum formed post-mining.  So, I am calling this specimen of white fibers from Alum Gulch (maybe, maybe not the Chief Mine) an Alum Group Mineral.

Photos (~4000 Kelvin) of fragile fibers of an Alum Group mineral from Alum Gulch, Harshaw District, Arizona.  Width FOV ~

And, what are Alum Group Minerals?  The generic chemical formula for Alum Group Minerals is XAl(SO₄)₂-12H₂O where X is usually an alkali metal cation with an oxidation state of 1+, usually sodium or potassium but ammonia, titanium or even cesium are available.  Those cations bond with an aluminum cation with an oxidation state of 3+, or occasionally bond with 3+ chromium, cobalt, iron or manganese.  Together those cations then combine with the sulfate radical, SO₄, and lots of water H₂O. 

Photomicrographs (LED ~5600 Kelvin): Fibers of Alum Group mineral from Alum Gulch.  Width FOV ~ 

Alum minerals most common in nature are referred to as Alum-K and Alum-Na. It is really tough to distinguish between these two minerals without some electronic gizmos---at least for me.  Both are soft at Mohs 2-3, form small, vitreous crystals, or fibrous mats, or are massive/granular.  Some crystals are clear and transparent while others are white and opaque.  Both are members of the Isometric Crystal System; however, MinDat noted that crystals are octahedral if they precipitate from pure water but are cubic if they precipitate from an alkaline solution. It appears most descriptions of mineral producing localities use the term Alum Group Minerals although most of these minerals are probably Alum-K.   


There are a couple of different alum minerals that have better mineral names: 1) lanmuchangite, known from two localities, where titanium with an oxidation state of 1+ substitutes for sodium or potassium; and 2) tschermigite with ammonia, NH₄, acting as the monovalent cation.

Natural alum minerals are usually formed as a precipitate around volcanic fumaroles/vents, burning coal beds, or where iron sulfide and potassium/sodium minerals can oxidize.


 A large number of “alum group” minerals are now produced synthetically and used in industry, and alum may be produced from rocks/minerals by adding sulfuric acid to leucite, alunite, bauxite ore, or kaolinite. We know refined alum for its place in the spice rack (alum-K) where my mother used it to crisp home-canned dill pickles. My father had his own use for alum for when he cut himself shaving, he dabbed the cut with a “styptic pencil” (alum-NH₄).   Commercially, alum is used as a flocculating agent in water-purification plants, to size paper, as a binder in dyes, and as an ingredient in baking powder (among the many uses).


Parents of children needing a science project know about growing large, colored (food coloring), octahedral crystals of alum when seed crystals are tied to a thread and suspended in a saturated solution.  They are quite beautiful!

I found USGS Bulletin 582 by Schrader and others (1915) to make fascinating reading, all 372 pages. One of the best sections is his quote about some of the items in a “prospector’s kit” that were used to test for the presence of alunite, an alum mineral:

Boil the powdered sample with water or with hydrochloric acid for several minutes. After allowing the powder to settle pour off the liquid and repeat the operation to insure the removal of all soluble sulphates. Dry the powder and heat to a dull red. Again boil in water, and after settling pour off some of the clear liquid. To this add a small fragment or a solution of barium chloride. If the mineral is alunite a heavy white precipitate will form. To be sure that the water used in this test does not contain sulphates in solution it should be tested with barium chloride, and if it gives a marked precipitate it can not be used. For this test all that is required that is not included in a miner's or prospector's outfit is a little barium chloride, which can be carried in a small bottle or cartridge.


Do modern rockhounds, or even prospectors, have their own chemical lab in their “prospector’s kit”?

REFERENCES CITED

Anthony, J.W., Williams, S.A., Bideaux, R.A., Grant, R.W., 1995, Mineralogy of Arizona, Third Edition: University of Arizona Press, Tucson, Arizona.


Schrader, F.C., J.M. Hill, 1915, Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, United States Geological Survey: USGS Bulletin 582.

FOR THOSE INQUIRING MINDS

A styptic pencil is an antihemorrhagic agent — simply put, it helps constrict blood vessels so they’ll stop bleeding. It’s most commonly used to treat small wounds and cuts on the face and body. The main ingredient in a styptic pencil is anhydrous (the NH₄ monovalent cation) aluminum sulfate; an agent that restricts blood flow, allowing a cut to close quickly.


And who are the inquiring minds?  Ask Albert Einstein: "I have no special talents. I am only passionately curious." Children are such curious creatures, as are adults that retain an enquiring mind. They explore, question, and wonder, and by doing so, learn. When they are curious about something new, they want to explore it. And while exploring they discover. Through discovery, they learn. This positive cycle of learning is fueled by curiosity and the pleasure that comes from discovery and mastery.

CHASING THE BLUES: MINERALS AND MUSIC ALONG WITH ELWOOD AND JAKE

Elwood: What sort of music do you usually have here?

Claire: Oh we got both kinds, We got country, and western.

In this time of the Covid-19 pandemic and self isolation my mind wanders, as readers can tell from several of my postings, and my comments about the Blues Brothers! But at least it seems to work, and I and my family remain well.  I read a new book about every three days, play with the minerals, devour the newspaper, write letters to the editor (few are published), write/read several hours a day, watch a little PBS, exercise, and listen to the oldies music channel. Jake: That Night Train's a mean wine.  Not a strenuous day but not too exciting either; however, we have food and shelter and wellness and for this I am happy.  Actually I am learning much, not only about minerals, but about the world in general and wait for scientists to conquer the coronovirus.  Today, for some strange reason, my mind wandered over to the color blue and this posting is what came up!

Blue

Oh, so lonesome for you

Why can’t you be blue over me

Blue

Bill Mack but a big hit by LeAnn Rimes

Well it's one for the money, well it's two for the show

Well it's three to get ready, now go, cat go

But don't you step on my blue suede shoes

Well you can do anything but lay off of my blue suede shoes

Carl Perkins or Elvis Pressley

Devil with the blue dress, blue dress, blue dress,

Devil with the blue dress on

Mitch Ryder

Blues stay away from me

Uh-uh-uh, blues why don't you let me be

I don't know why you keep a-hauntin' me. and I guess that's why

Delmore Brothers

Got the blues, got the blues

Got the blues, got the St. Louis blues

Louis Prima

OK, what is your favorite color?  For me it is blue.  As John Lennon once sang, “The sun is up, the sky is blue” or Judy Garland’s “Somewhere over the rainbow. Skies are blue.” Thinking about blue: 1) there are more songs with blue is the lyrics than any other color; 2) blue is the only color to have a genre of music named after it, The Blues; 3) if one of our 50 states primarily votes for the Democrat presidential candidate, it is a “blue state” 4) and so it goes.

A poster, source unknown, advertising the Delmore Brothers.

What about your favorite Blues genre or blue in the lyrics song?  Well, as an ole rock and roller Carl Perkins and Mitch Ryder are tough to beat.  But my all-time favorite is the Delmore Brothers, “Blues stay away from me.”  The music is very haunting (probably because of the tenor four string guitar and the harmonica {Wayne Raney} and brings back memories of my youth when Saturday night dances were scattered across the rural areas of Kansas. Those dances usually presented a “big band” sound, or “hillbilly” music; rock and roll generally was confined to school dances.   Yea, I know very few readers have heard a recording by the Delmore Brothers!  But consider they were stars of the Grand Ole Opry in the 1930s and wrote more than 1000 songs. Perhaps Bob Dylan summed it up best: “The Delmore Brothers, God I really loved them! I think they’ve influenced every harmony I’ve tried to sing.”  So, there you know some of my strange secrets!

https://www.youtube.com/watch?v=YUk9UDoVyKk

Maybe you have a favorite "blue" movie?  Who could forget The Blues Brothers--It's 106 miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark and we're wearing sunglasses.   So, what about your favorite blue mineral?  I presume a large segment of the population would immediately state azurite, the copper carbonate. Others might spout turquoise or zoisite (tanzanite), opal, aquamarine, or numerous others.  I have espoused my views on blue minerals with numerous Blog postings and today have a couple of new, blue, copper arsenates: guanacoite and arhbarite.  You aren’t familiar with them? Neither was I until I found them in a dusty drawer of a small rock and mineral store and started reading.

Arhbarite, a hydrated copper magnesium arsenate [Cu₂Mg(AsO₄)(OH)₃], 
gets its “strange” name from the Type Locality in Morocco, the Arhbar (orAghbar) Mine.  It usually has a dark blue color, a vitreous to sub-vitreous luster, a blue streak, and often forms as botryoidal cluster of radially grown crystals.  However, at times the crystals are so tiny that the mineral appears massive. Arhbarite forms in the oxidized zone of polymetallic ore deposits due to percolating hydrothermal fluids and is usually associated with other copper arsenates such as conichalcite and guanacoite.  Arhbarite is a rare mineral only found in two localities, the Type and in Guanaco in Chile.

In fact, the “strange” name for the second mineral, guanacoite, comes from its Type Locality in the El Guanaco Mine (Atacama Desert, Chile).  The mine produces gold (primary commodity), silver, and copper (chalcocite, bornite, enargite, and covellite) from Eocene rhyolite.  It is both a subsurface and surface mine. In addition, the Mine is a source for numerous and colorful blue and green copper minerals, including copper arsenates.

Dark blue massive arhbarite vug (top) with light blue guanacoite  prismatic and bladed crystals (bottom).  Length (vertical in photo) of both minerals ~3 mm.

 

Closeup of above photomicrograph.

Dark blue arhbarite surrounded by prismatic crystals of guanacoite.  Maximum width of blue mass ~1 mm..

Guanacoite is similar to arhbarite in that it is a hydrated copper magnesium arsenate except it has additional water [Cu₂Mg₃(AsO₄)₂(OH)₄-4H₂O]. It has a pale blue to blue color, a white to light blue streak but most important for identification, it usually occurs as prismatic, acicular to bladed, translucent crystals.  Guanacoite is often found as tiny blades lining, or associated with, vugs of arhbarite.  Again, it is a rare mineral only known from the Type Locality, Morocco, and Spain.

RIP John Lewis: Freedom is not a state; it is an act. It is not some enchanted garden perched high on a distant plateau where we can finally sit down and rest. Freedom is the continuous action we all must take, and each generation must do its part to create an even more fair, more just society.

GRAND CANYON MINING: ORPHAN MINE & HALOTRICHITE

Writing a blog posing is like dropping a rose petal down the Grand Canyon and waiting for the echo.       Apologies to Dan Marquois
 

The November 19, 2019, posting described minerals, especially philipsbornite and osarizawaite, collected from the Grandview Mine located on Horseshoe Mesa within Grand Canyon National Park (GCNP).  The Mine had a long history of producing copper, and attracting visitors, until purchased and annexed into the Park in 1940.  Specimens continued to appear from the Mine (collected illegally) until “bat gates” closed the entrance in 2009.

I have now acquired a second specimen, halotrichite (originally in the collection of David Shannon, noted Arizona rockhound), collected from a mine near Grand Canyon Village in the Park—the Orphan (Lost Orphan; Orphan Lode) Mine.  I am indebted to George Munford of Northern Arizona University for the information in the paragraph below.  See George’s complete story at intermountainhistories.org.

 

Hogan built the Hummingbird Trail down to the mine entrance--not for me.  Photo Public Domain courtesy of GCNP.

The Mine was originally staked as a copper prospect by Danial Hogan (maybe with Henry Ward as a partner?) in 1893 and then Hogan upped the ante by filing a patented claim with Charles Babbitt in 1906.  The Mine was never a large copper producer and continued to struggle in the early 1900s.  This struggle was compound in 1919 when the Mine was incorporated into the new National Park.  By the late 1930s Hogan saw a new opportunity for his land and invested in building the Kachina Lodge for tourists. But more troubles hit Hogan as World War II essentially stopped the flow of visitors to the Park.  He ended up holding onto the claim until finally selling it in 1946, without ever hitting the big bonanza.  The new owners (several of them) continued struggling until rich uranium ore was discovered in 1951. “Big Mining companies” then moved in with money, purchased the claim, started mining, and greatly expanded the business during the “cold war” and uranium boom. Western Gold and Uranium, Inc. (the owners) built a tramway from the south canyon rim down 1800 feet where the Mine entered the side of the canyon wall.  Ore was transported up to the rim and then hauled to a processing plant in Tuba City, AZ. On May 28, 1962, President John Kennedy signed into law, Public Law 87-457, which permitted Western Equities, Inc. to mine uranium ore in Grand Canyon National Park, adjacent to the Orphan claim, in exchange for title to the claim in 25 years (1987) . The law specified that all mining would be underground and that the tram would be dismantled by 1964. The Federal Government would receive a royalty ranging from 5 to 10 percent on the ore produced (Chenoweth, 1986).  The tram was dismantled, and a 1500 foot shaft was drilled straight down from the rim and an elevator was installed.

 

Headframe of the Orphan Mine on rim of Canyon.  Photo Public Domain and courtesy of GCNP.

The tramway ran from the rim to the mine, 1800 feet of cable.  Book may be ordered from Grandcanyonorphan.com

For those of us in Colorado it is interesting to note that in 1967 the Orphan claim and related properties were sold to the Cotter Corporation of Roswell, New Mexico, and Canon City, Colorado. During 1967, the Cotter Corporation enlarged its mill at Canon City to process 400 tons per day in an alkaline leaching circuit and 100 tons per day in an acid circuit. A flotation cell was added to remove iron and copper sulfide minerals from the ore prior to alkaline leaching. The first ore was loaded for Canon City on rail cars at an Atchison, Topeka and Santa Fe Railway Company's siding in Grand Canyon National Park on September 27, 1967. Since Cotter's AEC contract had expired on February 28, 1965, all uranium produced after that date was sold on the private market to electrical utilities (Albrethsen and others, 1982).

By 1969 the mine had produced nearly 500,000, tons of ore that yielded about 4.2 million pounds of uranium oxide. By then Mine owners were going bankrupt due to rising production and transportation costs, and federal regulations. The National Park Service finally acquired the abandoned mine and surrounding acres in 1987.

As with many mines in the West, bankrupt owners left U.S. taxpayers a cleanup bill.  The Orphan Mine was declared a Superfund Site due to contamination by the uranium and we shelled out 15 million bucks to remediate the site.  Even today uranium mining companies want to mine near the Park and a wide variety of groups and citizens continue to fight this proposition.  In 2012, the Secretary of the Interior issued a 20-year temporary ban on exploration for new uranium mines (currently 831 active mining claims) on one million acres of public lands surrounding the Grand Canyon National Park.   Rep. Raúl Grijalva (R-AZ) introduced the Grand Canyon Centennial Protection Act to ban new uranium mines around Grand Canyon National Park forever. The bill passed the U.S. House of Representatives on October 30, 2019.  On December 19, 2019, Sen. Kyrsten (D-AZ) introduced a companion bill, S-3127, in the U.S. Senate; it is awaiting action.

 

Mining the breccia pipe.  Sketch courtesy of Chenoweth, 1986.

Early reports on the Orphan Mine by Max G. Kofford, chief mine geologist for Golden Crown and Western Gold and Uranium, attributed its origin to a cryptovolcanic structure or diatreme. However, as with the Grandview Mine previously described, the minerals at the Orphan Mine are concentrated in breccia zones situated alongside structural flexing features.  The ore bodies are a pipe-like structures entirely hosted in the upper Redwall Limestone and are associated with the Breccia Pipe Uranium District described by Wenrich and others (1992, 2018).  They noted  “the northern Arizona metallic district can be thought of as a paleo-karst terrain, pock-marked with sink holes, where in this case most “holes” represent a collapse feature that has bottomed out over 3000 ft (850 m) below the surface in the underlying Mississippian Redwall Limestone. These breccia pipes are vertical pipes that formed when the Paleozoic layers of sandstone, shale and limestone collapsed downward into underlying caverns.”  The base-metal ores (copper and silver) may be related to, or similar to, Mississippi Valley Type deposits where emplacement of ores suggest low temperatures (as opposed to hydrothermal emplacement).  Perhaps even more interesting in today’s geopolitical world is that Rare Earth Elements (REEs), and especially Heavy Rare Earth Elements (HREEs), are significantly enriched in the uraninite (UO₂) found in many breccia pipes.  “Mixing of oxidizing groundwaters from overlying sandstones with reducing brines that had entered the pipes due to dewatering of the Mississippian limestone created the uranium deposits” (Weinrich and others, 2018).  I wonder if REEs are also present at the Orphan?

Halotrichite crystals/fibers on matrix.  Width FOV ~9 mm.  I remain uncertain about the golden/yellow grains and the black grains; they may be some of the uranium minerals.

So, the lonely mineral I have from the Orphan is halotrichite, a hydrated iron aluminum sulfate [FeAl₂(SO₄)₄-22H₂O]. The mineral is interesting in that it usually appears as acicular or hair-like fibers that may form tuffs, matted crust-like aggregates, or efflorescence.  The colors are usually pastels-white, colorless yellowish, greenish and crystals are quite soft at ~1.5 (Mohs).  They have sort of a silky luster and are water soluble. Halotrichite may precipitate around hot springs and volcanic fumaroles or form as efflorescence in weathering sulfide deposits and oxidizing pyritic coals.

REFERENCES CITED

Albrethsen, Holger, Jr. and F. A. McGinley, 1982, Summary history of domestic procurement under U.S. Atomic Energy Commission contracts, final report: U.S. Department of Energy, Open File Report GJBX-220(82).

Chenoweth, W.L.,1986, The Orphan Lode mine, Grand Canyon, Arizona, a case history of a mineralized collapse-breccia pipe: USGS Open File Report 86-510.

Weinrich, K. J., G.H. Billingsley, and B.S. van Gosen, 1992, The potential of breccia pipes in Mohawk Canyon area, Hualapai Indian Reservation, Arizona: U.S. Geological Survey Bulletin 1683-D.

Weinrich, K.J., P. Lach, and M. Cuney, 2018, Rare-Earth elements in uraninite-Breccia Pipe Uranium District Northern Arizona in Delventhal, E. (ed), Minerals from the metallic ore deposits of the American Southwest symposium: Friends of Mineralogy-Colorado Chapter.

A LITTLE TIDBIT

In the late 1950s, the mining company believed the uranium lode extended beyond their claim into federal property.  In what appears to be some muscle, the company proposed building an 18 story, 800 room hotel overhanging the rim. This grand hotel would spill “down the side of the precipitous cliff like a concrete waterfall” ending at a swimming pool and sun deck below.  The mining company thought that the public would much better like a small uranium mine in their Park rather than a giant hotel.  Put some pressure on the Park Service!!  The compromise was the 1962 Kennedy Law with the hotel taken off the drawing board.  Photo above courtesy of GCNP. 

Not all holes, or games, are created equal.   George Will