Sunday, November 24, 2019

DENVER SHOW HAMBERGITE, LAMPROPHYLLITE, & KLEINITE



 
The most unique specimen in the Show: Cave pearl nest, Ouray County, Colorado.
The Denver Area Mineral Dealers held their fall 2019 Gem and Mineral Show at the Jefferson County Fairgrounds on November 15-17.  I have attended this event for the last several years; however, I was rather underwhelmed this fall.  I thought the number of dealers decreased this year and some of those in attendance had decreased the size of their offerings.  In addition, the Friday buyers seemed low in numbers, especially for a free show.  However, every rock and mineral show represents a “good day” and I enjoyed my time visiting with the dealers and coming home with a couple of purchases.
 
The most unique name for a mineral dealer: O'Dark Thirty Boyz Mining.

Joe and Susan Dorris of Pinnacle 5 Minerals out of Colorado Springs brought a great display of amazonite, smoky quartz, topaz and jewelry.


At a show like this, an event that attracts all types of collectors and buyers, one sees the same common minerals over and over—how many South American amethyst crystals are for sale?  Therefore, I gravitate to dealers who often have some nice, rather uncommon, mineral specimens that are offered at a reasonable price (at least what I consider reasonable).  Dan, of Dan’s Used Rocks, is one of those dealers where I enjoy perusing his specimens, especially the thumbnails.
 
Buyers cluster around the thumbnails at Dan's Used Rocks.
Although I am fairly new to mineral collecting, I attend several shows per year but have never seen specimens of hambergite, kleinite or lamprophyllite “for sale.”  I am certain that more serious collectors would sort of chuckle and say something like “newbie, look a little harder.”  But, I found these minerals interesting and they came home with me!
Hambergite is ”an especially rare and unusual collector’s stone…and a lesser-known gemstone” (gemselect.com).  It is a beryllium borate hydroxyl [Be2(BO3)(OH)] that is associated with beryllium bearing granite pegmatites as an accessory mineral  although it was first described from a nepheline syenite in Norway. The orthoborate ion (BO3) of hambergite is the simplest of the boron’s different ions. It has three oxygen ions surrounding a central boron ion in the shape of a triangle.  Each of these ions can then share the oxygen ions of other “triangles” and form larger units.  The boron ion has an oxidation charge of 3+ while each oxygen ion (3 total) has an oxidation number of 2- so the total orthoborate ion has a total charge of 3- and is an anion. 
 
The orthoborate ion as drawn by chemspider.com.  Each oxygen has an oxidation number of 2- while the boron has an oxidation number of 3+. (BO3)

The hydroxyl [(OH)] in hambergite [Be2(BO3)(OH)] is also an anion with a total oxidation number of 1- since the hydrogen is a 1+ and the oxygen a 2-.  Each beryllium ion, there are two of them, has an oxidation number of 2+ for a total of 4+ for the cation.  That 4+ balances the 3- and 1- for the two anions. There, I have just been practicing my limited knowledge of chemistry trying to learn a wee bit more!

So, how do you do it? No, not make a baby but balance an equation?  I had biology last year.        Hank Green

Hambergite is an Orthorhombic mineral where crystals are usually prismatic (long) with good cleavage, and white (often with a pale-yellow sheen) to colorless (the rare gem variety).  It has a vitreous luster, a white streak and is transparent (colorless variety) to translucent (white variety).  It is very brittle, quite hard at ~ 7.5 (Mohs), commonly striated along the prisms, and some crystals are terminated.

Partial crystal of hambergite.  Width of crystal is ~1 cm.  The unseen "thickness" is ~4 mm.  Terminations of hambergite commonly are etched.

Striations noted parallel to long C Axis.  The etching of the termination shows clearly.

The specimen I acquired is a rather flattened, white, striated, prismatic crystal that is etched at the termination..  It was collected near Rangkul in the region of Gorno-Badakhshan in Tajikistan.  I just cannot find out much information about the geology of Rangkul except that it is in the high plateaus located in the Pamir Mountains, a region of tectonic plates activity.  My guess is that the hambergite formed in miarolitic cavities in the Mika pegmatite along with lepidolite, microcline, albite, quartz, schorl, elbaite, topaz, muscovite, apatite, fluorite, calcite, barite, beryl, and cassiterite (Jambor and others, 2000).

More than 50% of Tajikistan is above 10,000 feet in elevation.

I was not overly familiar with the Kola Peninsula except to realize that it was a hunk of land in extreme northwestern Russia above the Arctic Circle bordering northern Finland.  I now realize that the Peninsula is part of the Baltic Shield, a now stable area where rocks underwent extensive mountain building events during the 2.5-2.0 Ga Lapland-Karelian-Kola Orogen (Precambrian). The Kola Peninsula is also an important ore base for Russia’s metallurgy industry.  It is very rich in titanium, apatite, nephelines, copper, nickel, mica, kyanite, iron ore, and other precious metals and rare-earth elements (Mitrofanov and others, 1995).

So, I have a specimen of lamprophyllite from the Murmansk (the capital) Oblast (an official district or province) in the Kola Peninsula (a geographical term). The mineral is a titanium silicate with a chemical formula that is amazing: [(Na,Mn)2Ti,Fe)3(Si2O7)2O2(OH,O,F)2].  The mineral is yellow to yellow brown to brown and the crystals are usually acicular (needle-like) radiating from a center.  The crystals are flattened and belong to the Monoclinic Crystal System (3 axes of unequal length).  They are translucent, very brittle and leave a brownish white streak on unglazed porcelain.  Crystals are very soft at ~2.5 (Mohs) and have a luster ranging from vitreous to pearly. The name, lamprophyllite, comes from the shiny cleavage planes parallel to the prisms.

Acicular crystals of lamprophyllite showing cleavage planes parallel to long axes. Width FOV ~1 cm.    


Crystals of lamprophyllite radiating from a common point, the typical arrangement of the mineral.  Width FOV ~1.7 cm.

Lamprophyllite at its type locality in the Murmansk Oblast (a mountain range named the Lovozero Massif) is found in extrusive rocks indicative of volcanos in a continental rift basin.  These rocks are termed peralkaline and are very deficient in aluminum with abundant sodium-rich pyroxene and amphibole minerals.  The Massif rocks seem to be rich in obscure minerals such as pyrophyllite and rare earth minerals.  As MinDat notes, pyrophyllite is found at the Gem Park Complex in Fremont County, Colorado, an area previously mined for rare earth elements in an intrusive dike.

Although most of the Kola Peninsula lies above the Arctic Circle, proximity of the Oblast to the Gulf Stream leads to unusually high temperatures in winter. 

Kleinite is a rather rare mineral that is only found in three localities around the world—Germany, Texas and Nevada.  The best known of these locations is the McDermitt Mine, Opalite District, Humbolt County, Nevada. The McDermitt is just one of several mines that are located in the Opalite Mercury Mining District that straddles the Nevada-Oregon State Line,  The District is associated with a volcanic caldera complex where eruption centered around a Miocene age of ~16 Ma (Henry and others, 2016).  The original mercury mineralization was in the Cordero Rhyolite, but later hydrothermal action deposited the metal into nearby lake or stream-deposited tuff (volcanic ejecta) (Henry and others, 2016). Mercury in the caldera complex was first mined in the 1970s and the operations ceased in 1990. Porter GeoConsultancy noted that the McDermitt Mine was the most important mercury producer in the Americas during the 20th century producing 279,000 flasks to 1988 (geoconsultancy.com.au).  The minerals cinnabar (mercury sulfide HgS) and corderoite (mercury sulfide chloride Hg3S2Cl2) yielded almost all of the mercury; kleinite was just an insignificant rare accessory mineral. 

Bright yellow to orange adamantine kleinite. Width FOV ~1.9 cm. Note "earthy" crust in right central.

Lower half of photo is kleinite. The blue-purple is opal. I remain uncertain about the crust in the top half.  Width FOV 2.2 cm.


Same situation as above. Adamantine kleinite on left with yellow crust on right.  Is the crust kleinite?  Or is it another  mercury mineral? Width FOV ~1.3 cm.
This photo may be a mixture of mercury minerals.

Adamantine kleinite with a single well-defined crystal near top.  Crystal length ~1.5 mm.

So, kleinite is sort of the lost kid at the mercury mines and is quite rare. The crystals have a vibrant yellow (canary) color ranging to light yellow—often on the same specimen. If left in the daylight the color transforms to orange or reddish yellow; hide the specimen in a dark box and the original color comes back.  It has a yellow streak and is soft at ~3.5 (Mohs).  Crystals are short prismatic and hexagonal, although not equidimensional.  Kleinite can also occur as a “crust” with a massive appearance.  Crystals appear to be translucent rather than transparent; I would call the “crust” opaque. The luster ranges from adamantine to greasy/earthy. There is also a distinct possibility that the earthy crust may not be kleinite but one of the other rare mercury minerals present in the District.  I simply do not have the skills to call the shot.

TIDBITS FROM THE 2019 UNITED STATES GEOLOGICAL SURVEY MINERALS YEARBOOK, MERCURY 2019

Mercury has not been produced as a principal mineral commodity in the United States since 1992. In 2018, mercury was recovered as a byproduct from processing gold-silver ore at several mines in Nevada; however, production data were not reported. Secondary, or recycled, mercury was recovered from batteries, compact and traditional fluorescent lamps, dental amalgam, medical devices, and thermostats, as well as mercury-contaminated soils. It was estimated that less than 40 tons per year of mercury was consumed domestically. The leading domestic end users of mercury were the chlorine-caustic soda (chloralkali), dental, electronics, and fluorescent-lighting manufacturing industries. Only two mercury cell chloralkali plants operated in the United States in 2018. Until December 31, 2012, domestic- and foreign-sourced mercury was refined and then exported for global use, primarily for small-scale gold mining in many parts of the world. Beginning January 1, 2013, export of elemental mercury from the United States was banned, with some exceptions, under the Mercury Export Ban Act of 2008. Effective January 1, 2020, exports of five additional mercury compounds will be banned. 

An inventory of 4,437 tons of mercury was held in storage at the Hawthorne Army Depot, in Hawthorne, NV. The Mercury Export Ban Act of 2008 required the U.S. Department of Energy to establish long-term management and storage capabilities for domestically produced elemental mercury. Sales of mercury from the stockpiles remained suspended.

China, Kyrgyzstan, Mexico, Peru, Russia, Slovenia, Spain, and Ukraine have most of the world’s estimated 600,000 tons of mercury resources. Mexico reclaims mercury from Spanish colonial silver-mining waste. In Spain, once a leading producer of mercury, mining at its centuries-old Almaden Mine stopped in 2003. In the United States, there are mercury occurrences in Alaska, Arkansas, California, Nevada, and Texas; however, mercury has not been mined as a principal mineral commodity since 1992. The declining consumption of mercury, except for small-scale gold mining, indicates that these resources are sufficient for centuries of use.

REFERENCES CITED

Henry, C. D., S. B. Castor, W.A. Starkel, B.S. Ellis, J.A. Wolff, W.C. McIntosh, M.T. Heizler, 2016, Preliminary geologic map of the McDermitt caldera, Humboldt County, Nevada and Harney and Malheur counties, Oregon. Nevada Bureau of Mines and Geology Open-File Report 16-1.

Jambor, J.L., E.S. Grew, A.C. Roberts, 2000, New Mineral Names: American Mineralogist v. 85. 

Mitrofanov, F.P., V.I. Pozhilenko, V.F. Smolkin, A.A. Arzamastsev, V. Ya. Yevzerov, V.V. Lyubtsov, E. CV. Shipilov, S.B. Nikolayeva, Zh. A. Fedotov. (Edited by F.P.Mitrofanov), 1995: Geology of the Kola Peninsula: Apatity. 

ANOTHER TIDBIT: Members are the lifeblood of the CSMS. The officers are the brain that makes the organization move in the right direction.  The Show Director, Field Trip Coordinator, and Webmaster represent the legs that muscle the club so that it stands out to the community.  But the heart of CSMS is the Editor of the Pick n Pack

I have been writing for the Pick n Pack for over a decade and had the privilege and joy of working with a number of editors who have produced an excellent product.  I would estimate that in the last ten years the Pick n Pack editors and writers have garnered more awards in the RMFMS and AFMS than any club in the Federation.  I want to take this opportunity to thank the current editor, Taylor Harper, for his yeoman’s work during this last year.  Unfortunately Taylor is leaving his editorial post at the end of the year (work related).  Thank you, Taylor, and I will miss you. 

Monday, November 18, 2019

GRAND CANYON MINING: PHILLIPSBORNITE & OTHERS



It is always nice to run across minerals at a show that you recognize as coming from a mine or area that no longer is available for collecting.  At the 2019 Tucson Show I was rummaging around Shannon and Sons Minerals and was delighted to find a specimen of philipsbornite (an arsenate) that was collected from the Grandview Mine in northern Arizona.  I then remembered that somewhere in my home collection thee was a specimen of aurichalcite from the Grandview that I had picked up at the Colorado Springs show a few years ago.  That little tidbit may seem insignificant to many readers; however, The Grandview Mine (AKA Last Chance Mine, Canyon Copper Mine) is located on Horseshoe Mesa in Grand Canyon National Park.  Most us know that mineral collecting is prohibited in national parks.  So, how did these specimens arrive in my collection?
A USNP sign above the mine states: “In 1890 prospector Pete Berry staked the Last Chance copper claim 3,000 feet below you on Horseshoe Mesa.  The Last Chance Mine began a 17-year flurry of activity here at Grandview Point.

For a while the Last Chance Mine thrived.  The ore was rich; it claimed a World Fair’s prize in Chicago in 1893 for being over 70% pure copper.  But the high cost of packing ore to the rim, then shipping it to be refined, doomed the operation.  Berry and his partners sold the mine in 1901 to Canyon Copper Company.  The new owners continued mining but ceased when copper prices plunged in 1907.
Workers at the Grandview Mine, or at least posing as workers in 1907. Photo courtesy NPS.
Mining on Horseshoe Mesa, though short-lived, had a lasting impact.  Grandview became Grand Canyon’s most popular tourist area for about 10 years when Grand Canyon tourism was in its infancy. [Along with his mining endeavors, Berry and wife Martha started a tourist business at Grandview Point in the early1890s that remained the South Rim’s most popular destination until 1901. (Anderson, 2000)] The Grandview Trail, built by Last Chance miners to reach their mines now serves thousands of hikers each year.”
Grandview Mine.  Unknown date.  Courtesy NPS.  


 Photo: AHS.0743.00011. Bill Cameron Collection. Cline Library, Northern Arizona University.

Ascarza (2014) noted that “Ore was transported from the drifts to the top of Horseshoe Mesa using a mule-powered hoist, then taken by pack train on the four-mile long Grandview Trail. 

The mules carried 200 pounds of ore per trip, averaging a trip and a half a day. Afterwards, the concentrate was hauled by wagon to Apex Junction and shipped by rail to the El Paso smelter.”  

Ross (1972) in nominating the mine area for the National Register of Historic Places stated: “A few years later [after 1907], William Randolph Hearst acquired the property and in 1940, he sold it to the National Park Service.”  I was uncertain about the mine history from 1907 to 1940 until I located some NPS historical documents that noted: “ William Randolph Hearst’s acquisition of Pete Berry’s and the Canyon Copper Company’s patented lands in 1913,totaling207.7acres,posed a much greater threat, as the newspaper magnate clearly had the political clout to disregard informal pressure and the capital to develop anything he wished. Hearst did taunt the NPS with rumors of grand develop-mental schemes but generally cooperated with authorities, agreeing to exchange 48.9acres at Grandview Point for 25.8acres elsewhere in 1926, and occasionally discussed the gift or sale of his lands to the government. Cooperation vanished, however, when Hearst’s attorneys once again broached the subject of a sale and the NPS responded with a Declaration of Taking in September 1939. Park officials sustained criticism from the regional press, chambers of commerce, local residents, and the county board of supervisors for employing condemnation, the only time it has done so in park history, and for offering only $25,000for the prime real estate. Hearst’s appraisers estimated its value at$367,000, and his lawyers fought for the higher figure until October 1941, when federal judge David W. Ling ordered the payment of $85,000. The taking, however, was legally effected in July1940.” (National Park Service, 2019).

I presume then that collecting of minerals from the Grandview Mine became illegal after the incorporation into Grand Canyon National Park (although I noted a specimen shown on MinDat.org was collected in 1966, another in 1997).  However, many years ago I asked geologists in Arizona about Grandview specimens seeing daylight.  A few informed me that collectors and/or tourists had often visited the mine after 1940 and illegal collecting did not finally cease until “bat gates” were installed in 2009.  These gates protect the Townsend's Long-eared bat colony, and various cultural artifacts, while keeping out human trespassers. 
Bat gates installed at Grandview Mine.  Photo courtesy of NPS.
Bat gate worker eying a mineral specimen in the Grandview Mine.  Photo courtesy of NPS.

As I understand the situation (sometimes that is a stretch) the copper minerals were concentrated in breccia zones situated alongside structural flexing features.  MinDat.org stated, and this is important later on in this story, the “ore body is a pipe-like body [entirely] hosted in the upper Redwall Limestone.”  The Grandview Mine is the most famous mineral locality of these breccia pipes  (Anthony and others, 1995) and is associated with the Breccia Pipe Uranium District described by Wenrich and others (2018) and presented at the Metallic Ore Deposits of the American Southwest Symposium sponsored by the Friends of Mineralogy, Colorado Chapter.  I attended the August symposium but do not remember if she specifically mentioned the Grandview Mine.

Wenrich and others (1992, 2018) 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).
 
The breccia pipe at Grandview is restricted to the Redwall Limestone (the dark blue layer near the bottom).  The uranium (the red blob in the brown layer near the middle), and hence the REEs and HREEs, accumulates in rocks younger than the Redwall and higher in the stratigraphic section,  Weinrich and others (2018) describe this schematic drawing as representing a typical, "complete" breccia pipe.
Besides the gold and silver the breccia pipes attracted the attention of the U.S. Atomic Energy Commission as they searched for uranium.  “In 1951, the U. S. Atomic Energy Commission contracted with Dr. Russell Gibson, Harvard University to make a radiometric reconnaissance survey of "red bed" copper deposits in the south-western United States for their uranium content, and possible production capabilities. He examined 36 properties in 4 states -Arizona, New Mexico, Texas, and Oklahoma. Properties examined in Arizona were the Anita Mine, Grandview Mine, White Mesa district, and the Warm Springs district. The old Grandview copper mine in Grand Canyon National Park exhibited the greatest uranium concentration of all the 36 properties examined.” (Arizona Geological Survey, 2019).
Perhaps even more interesting in todays 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 wondered if REEs are also present at the Grandview Mine.

According to MinDat.org the Grandview Mine has produced 32 valid minerals and is the type locality of grandviewite, a copper aluminum sulfate (Cu3Al9(SO4)2(OH)29).  Anthony and others (1995) noted that erosion has removed large amounts of overlying rock and has resulted in the oxidation of the primary minerals.  A suite of secondary copper, zinc, iron, uranium, and arsenic minerals such as cyanotrichite, brochantite, chalcoalumite, langite, metazeunerite, scorodite, olivinite, and adamite was then preserved.  MinDat did not list uraninite as occurring in the pipe—with good reason, I guess! Weinrich and others (1992) believed that breccia pipes restricted to the Redwall Limestone have little or no uranium and REE potential since those pipes that do contain elevated gamma radiation (as at Grandview), the anomalies are entirely restricted to downdropped sandstone blocks from the Surprise Canyon Formation or the lower part of the Supai Group.
MinDat.org did note the presence of the radioactive copper uranium arsenates zeunerite and metazeunerite at Grandview. 
 
One of the specimens in my collection from the Grandview Mine is aurichalcite, a secondary zinc copper carbonate [(Zn,Cu)5(CO3)2(OH)6].  The crystals are pale green-blue, prismatic and lath-like that often radiate from a single point and cover the matrix (??gypsum).  They are “typical looking” aurichalcite crystals.
Crystals of aurichalcite.  Each individual is submillimeter in width.

"Cluster" of aurichalcite crystals.  Width FOV ~2.5 cm.
 
Blue-green crystals of aurichalcite covering a matrix.  Width FOV ~3.6 cm.

The really interesting specimen I acquired from Grandview is the rare lead aluminum arsenate, philipsbornite [PbAl2(AsO4)AsO3OH)(OH)6].  Philipsbornite is usually associated with lead deposits as a secondary mineral such as at the Red Lead Mine in Tasmania, Australia (home of the famous crocosite). Although several articles refer to the Grandview Mine as the single locality in the U.S. for philipsbornite, recent notes have indicated a second locality in Montana (see MinDat.org).

Philipsbornite from Grandview is usually an earthy mass of tiny, yellow to yellow-orange, indistinguishable crystals.  If not in an earthy mass, it can be somewhat hard at ~4.5 (Mohs) and have a vitreous luster.  It just looks sort of dull except that it is studded with blue crystals that have been identified as osarizawaite and green aggregates that may be brochantite.  Now, osarizawaite (an iron aluminum copper sulfate; [Pb(Al2Cu)(SO4)2(OH)6]) is usually listed as having green or teal blue or green-yellow color.  However, a Michael Kline photo on the MinDat.org Grandview Mine gallery describes his specimen as “Yellowish clusters of minute Philipsbornite with blue Osarizawaite and green Brochantite.” Description of a similar specimen shown on findingrocks.com states, “ the Osarizawaite is the finest I've seen for the species, featuring crystals of unusual size, form, clarity, and color-- deep blue! The green crystals have not been analyzed but appear visually similar to the omnipresent Brochantite on Grandview specimens.  So, I am sticking with the tiny blue to blue-green crystals as the uncommon osarizawaite.  Whatever, the specimen has some unusual copper minerals and I feel “lucky” for being able nab them at a show.
Photomicrographs of yellow-orange, vuggy phillipsbornite with blue osarizawaite.  Width FOV ~1.4 cm.
 
Phillipsbornite, osarizawaite with green brochantite.  Width FOV ~ 6 mm.
There are specimens from the Grandview Mine out there in the mineral world, but they do not often appear on the market.  With the bat gates now locked, and collecting prohibited, any specimen is probably from some collector breaking up their collection.  However, I noted that in 2010 more than 1,200 mineral specimens from the Grandview Mine were added to the Grand Canyon National Park’s Museum Collection (Grand Canyon National Park, 2012).  You may download Quest For The Pillar of Gold (22.5 MB PDF file) a Grand Canyon Association monograph about mining and miners of Grand Canyon.

REFERENCES CITED

Anderson, M.F., 2000, Administrative History of Grand Canyon National Park:  Grand Canyon Association, Monograph 11.

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

Arizona Geological Survey, 2019: docs.azgs.az.gov/OnlineAccessMineFiles/G-L/Grandview...

Ascarza, W., 2014, Mine Tales: Mules aided Grand Canyon’s Grandview site: Arizona Daily Star, July 21, 2014.

Grand Canyon National Park, 2012, Canyon Sketches: V. 25.
Holland, F.R. Jr, 1972, National Register of Historic Places Inventory-Nomination:  Last Chance Mine. 

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.