REDO #2 TUCSON: COPPER, ANATASE, VESUVIANITE; GROSSULAR & TITANITE

 

In a previous posting I noted that a two-day excursion to the Tucson 2021 Redo was enjoyable and I came home with a few treasures!  Of course, I consider most of my buys as treasures although a few stinkers appear now and then.  Remember, as Bob Jones coined the term, I am a frugal collector.  I purchase less expensive specimens that “make me happy.”  I am not collecting for exhibits, or even local mineral shows, but for specimens that I can study and learn from.  Being a life-long learner is a high priority in my life!  Life is too short to be anything but happy.

Happiness, true happiness, is an inner quality. It is a state of mind. If your mind is at peace, you are happy. If your mind is at peace, but you have nothing else, you can be happy. If you have everything the world can give - pleasure, possessions, power - but lack peace of mind, you can never be happy.            Dada Vaswani   

Living in the Plains, Midwest, and West over the decades, I am not overly familiar with the geology of the Appalachian chain  of mountains. Oh, I have driven through and camped several times, I can spout off the creating orogenic events, and the physiographic provinces, etc. but outside of a few famous collecting localities/mines I remain a novice learner when it comes to the minerals.  That is one reason I enjoy the professional, but semi-hard core, journals like Mineralogical Record and Rocks and Minerals. I joined the Baltimore Mineral Society to get a non-western U.S. perspective on geology and minerals and now read several eastern mineral club newsletters if they are available on the Web.  Life is interesting.

I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.    Henry David Thoreau

At the Show I was able to pick up a hunk (5 cm. X 8 cm) of mostly native copper with a little calcite and perhaps a few other minerals. It had been cleaned with acid so the copper would show and looked like the nuggets from Michigan that originally had been released from the Precambrian basalt by Pleistocene glaciers.  However, my purchased specimen came from the Blue Ridge portion of Pennsylvania, a state that I did not realize produced copper. The Pennsylvania Geological Survey noted that a small area (about 1- by 5-mile belt) contains trace- to minor amounts of native copper in Adams and Franklin Counties and my specimen was labeled as collected from Pine Mountain, Adams County. This is a general location of native copper deposits lying west of Blue Ridge summit.  MinDat notes the presence of native copper in epidotic rhyolite, massive quartz and associated secondary copper minerals.  No specific quarry or prospect was noted with my specimen.  Unlike the Michigan nuggets that were released and transported by glaciers, the Pennsylvania copper belt fell ~35 miles short of glacial activity so copper nuggets were never released from their enclosing metabasalt (part of the Precambrian Catoctin Formation). The Pennsylvania Geological Survey has identified eight named mines, and numerous small prospects, that are known in the native-copper belt, but production has always been minimal. Unlike many copper deposits in the western U.S. that are associated with intrusions and hydrothermal activity, R.A. Landy, in a 1961 unpublished Ph.D. thesis at Penn State, believed[M1]  that the native copper deposits were developed from the rearrangement and reconcentration of the copper originally present in the rock itself (the metamorphosed basalt).  The original basalt came from flows resulting from crustal expansion in the late Precambrian—continents or proto-continents pulling apart.

Copper nugget from Pine Mountain, Pennsylvania.  Width ~7.5 cm.

I also picked up four specimens from Lehman Minerals, collectors on the opposite side of the country—the White and Inyo Mountains of California.  Chris Lehman is headquartered in Bishop, the only city in Inyo County and situated at the head of Owens Valley between the Sierra Nevada (on the west) and the White Mountains (on the east).  The Whites are interesting from several points of view including the presence of Late Proterozoic (latest Precambrian) rocks that represent sediment shed off the early North American (in today’s geography) continent.  These rocks confused geologists for decades as they often contained fossils older than the Cambrian trilobites (and commonly were soft bodied).  Were they Cambrian in age? Or Precambrian? They were often referred to as being Eocambrian in age, but stratigraphers finally settled on Ediacaran (see Posting April 13, 2017) for that particular period of time.

Above these Precambrian rocks is a thick section of mostly shallow water marine sedimentary rocks of Cambrian (a continuation from the Ediacaran) and Ordovician age. However, the Ordovician sedimentary rocks, along with a thick section of later Mesozoic metasedimentary and metavolcanic rocks were brought into the Whites (current geography) from the northeast sliding along large scale thrust faults.  Geologists call these foreign rocks allochthonous rocks.  This turmoil continued and in the Mesozoic all sorts of crap broke loose as the Pacific Plate and others (mostly microcontinents) were banging into the North American Plate with the former being subducted beneath the latter (although some western rocks were stuck onto the North American Plate).  The subduction, with later heat and melting at depth, resulted in large scale plutonic events (magma rising towards the surface but cooling and crystallizing before reaching the surface).  Such was the case in the White Mountains but to the west the Sierra Nevada plutonic event was even more massive as these mountains are much larger that the White Mountains.  The collision of these plates rippled across western North America creating orogenic events as it proceeded.  The Cenozoic was marked by two major “happenings”: massive volcanism, especially in the mid to late Tertiary; and the crustal extension resulting in the creation of the fault block mountains of the Basin and Range.  In fact, the White Mountains are the westernmost range of this physiographic province.

The above explanation of the geology of the White Mountains is not very understandable and is critically short on details.  However, there are hundreds of professional papers scattered in libraries, and sometimes on the Web, that would be tough to synthesize in a posting like this.  The geology is complicated!

I have yet to see any problem, however complicated, which, when looked at in the right way did not become still more complicated.     Paul Anderson

Chris Lehman has a collecting locality east of Bishop that MinDat refers to as the Lehman Anatase Prospect. I am fairly certain two of my four specimens came from that location; however, the other two specimens are listed as from the “White or Inyo Mountains.”   I suppose they are proprietary locations. 

One specimen from the Lehman Prospect consists of water clear and terminated quartz crystals arranged in a spray.  The anatase occurs as inclusions within the quartz with additional anatase crystallizing on the exterior. The Quartz Page defines three types of inclusions in quartz: 1) Protogenetic where the minerals formed before the quartz and were engulfed by the growing quartz; 2) Syngenetic where the inclusions and the quartz grow simultaneously; and 3) Epigenetic where during the growth of the quartz crystal there is a pause that allows new incompatible elements into the crystal structure.  The specimen from the Lehman shows syngenetic crystals of anatase embedded in the quartz and are termed phantom crystals.

Water clear quartz crystals mounted on a pin (white).  Note anatase inclusions and external growths. Length of largest quartz crystal ~1.2 cm.

A second specimen from Lehman is a larger quartz crystal covered with quite tiny greenish brown crystals of anatase with a few crystals of adularia (potassium aluminum silicate).  The large crystal may also be included; however, the exterior growth prevents peeking into the quartz.

Quartz crystal with heavy anatase inclusions and upper crystal face covered with very tiny crystals.  Note two adularia crystals.  Length of large quartz crystal ~3.5 cm.

Adularia crystals each about 2 mm.

Green anatase crystals ~.5 mm, or less, in length.

Anatase is a titanium oxide, one of three polymorphs of TiO₂—the other two being rutile and brookite.  There seems to be at least three other forms of titanium oxide that were identified in meteorites and therefore are exceedingly rare. Anatase is the least stable of the polymorphs and forms at lower temperatures and at later stages in crystallization, often associated with quartz and adularia. Belonging to the Tetragonal Crystal System, anatase usually appears as tabular or “double pyramid” crystals and are usually “green” or brown (although crystals may have a variety of colors).  It has a metallic luster is essentially opaque with a hardness of ~6 (Mohs). Titanium oxide is mostly found in metamorphic rocks and pegmatites.

The small adularia crystals [KAlSi₃O₈] belong to the Feldspar Group and actually are a low temperature variety of orthoclase (a potassium or K Feldspar).  Adularia crystals commonly are glassy and transparent and often tough to identify unless they have a moonstone sheen and play of colors.

A third specimen is from the nearby Inyo Mountains and is a single, prismatic, pretty ugly, crystal of epidote [(Ca₂)(Al₂Fe⁾(Si₂O₇)(SiO₄)O(OH)]  with an attached tiny, twinned crystal of  titanite, a calcium titanium silicate (CaTi(SiO₄)O), formally called sphene due to its wedge shape.  Crystals have an adamantine luster, are translucent to transparent with a white streak and a hardness of ~5.5 (Mohs).  It appears in igneous and metamorphic rocks. Not an exceptional specimen but one that is interesting with the attachment.

Titanite twin attached to epidote.  Total length of epidote ~8mm.

The 4^th Lehman specimen is a group of vesuvianite crystals on a matrix of grossular (Garnet Group).  The vesuvianite [Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH,F)₄] forms beautiful crystals that are either long prismatic and columnar, or short pyramids, with a greenish yellow to yellow brown color.  They have a vitreous luster, are brittle and fracture easily, and a hardness of ~6+ (Mohs). Most crystals on this specimen are fairly translucent.  Vesuvianite usually form in skarn deposits (limestone subject to contact metamorphism). See a previous Posting, November 18, 2012, for additional information.

Crystals of vesuvianite.  Width FOV ~6mm. 

Mass of grossular garnets.  Width FOV ~6mm.

Grossular is a calcium aluminum silicate [Ca₃Al₂(SiO₄)₃] that often is some sort of a green color since it is named for the color of gooseberries. It is a common mineral in contact metamorphic zones associated with limestone, and is an associate of vesuvianite, wollastonite and diopside. 

The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.   Isaac Asimov

 

A REDO: TUCSON SHOW 2021, TAKE 2—THE APRIL EVENT

The Santa Catalina Mountains, topping out at over 9000 feet, greet visitors to Tucson.  The Catalinas, on their western front, generally expose late Precambrian igneous and metamorphic rocks intruded by a variety of mid Tertiary igneous rocks, especially the Wilderness Suite Granite seen from Catalina State Park. The Catalinas are one of the southwestern Sky Island ranges, isolated from other ranges, but related to continental stretching during the Tertiary "Basin and Range Orogeny".

Early this last winter a website was launched titled TheRock.Show and was designed as an internet sales event for dealers normally participating in the February Tucson Shows.  This site alerted me to the fact that a “mini-Tucson” was coming in spring 2021.  The Tucson Main Show in the downtown convention center had been cancelled several months ago; however, dealer venues scattered around Tucson were in the planning—an exciting opportunity.  As time went along, I was able to note that the dealers were opening April 10^th with “early openings" (often wholesale) before that date.  Shows were scheduled to continue, at the latest, to April 25^th; in reality, few shows lasted for two weeks and most folded up on the 18^th. 

All participants attending the April event were required to mask; most were in compliance.  

I am uncertain where all show venues were located around the city; however, the large (in most years) and popular Kino Gem and Mineral Show was moved to a nearby parking lot since the former locality was turned into a drive-in Covid-19 vax area.  Several hotels along I-10 had banners strung along the balconies and the Pueblo Show was “going” but reduced in size.  I only had a two- day window to explore the different venues so chose the 22^nd Street Show and the many dealers clustered in a variety of buildings called Mineral City (between Plata and Lester) along the Oracle main drag—north of downtown.

 

 

The Mineral Showcase Show of the Mineral City warehouses had a number of well known dealers with some mighty fine specimens.  As noticed in a photo above some of the dealer spaces looked more like a nice hotel room rather than a warehouse.  I continue to be fascinated by legrandite and ogled at the specimen (and price) provided by Evan Jones. 

Mineral City has several warehouses where individual rooms open to inside hallways—various sizes of rooms with the traditional warehouse/storage space sliding doors (this grouping was termed the Mineral Showcase Show).  I really don’t know the number of vendors that were present (maybe ?30) but I did have a chance to visit with Leonard Himes of Monument, Colorado, who displayed a variety of high end minerals.  However, my planned and initial visit was to one of my favorite dealers, Shannon Family Minerals of Gilbert, Arizona. Shannon’s is one of the few dealers where Perky & micromount boxes, fold up cardboard boxes, and Geo Tac mineral putty are available for same-day purchase.  They also have the largest inventory of minerals of which I am aware (I suppose Excalibur might be larger); however, Shannon’s inventory has grown exponentially since he recently purchased the entire inventory of Mineralogical Research Company (tens of thousands of minerals). A few flats were available at the Show and they supplied me with a few really interesting minerals (of course).

Flats of minerals displayed at Shannons. Chalcanthite, a hydrous copper sulphate, forms in arid climates where copper deposits rapidly oxidize, commonly on mine walls.  This specimen came from the Planet Mine, La Paz County, Arizona. 

Across the street from Shannon’s was another group of vendors clustered together in rooms that opened to the outside.  Among the dealers was Glacier Peak Minerals operated by the Joe Dorris family from Colorado Springs.  Glacier Peak is well known for the amazonite, smoky quartz, and topaz commercially mined from the Pikes Peak granites (and relatives) of late Precambrian age near Lake George (west of Colorado Springs).

Minerals for sale shown by Glacier Peak Mining.  Joe Dorris authored the many books shown.  

Day 2 of my show venture was spent perusing the great variety of goods displayed by vendors at the 22^nd Street Show (free but $5 parking).  This may have been the largest show in 2021 mini-Tucson (70+ vendors); however, I did not visit all major venues.  The 22^nd Street show is also visible to travelers along I-10 near downtown as dealers are housed in a long “giant tent” with smaller satellite tents on either end.  The extremely popular food court is between the main tent and a satellite tent.

I have frequented the Sri Lankan Curry Pot for the last several years on my visits to the 22nd Street Show.  What a feast!

The doors finally opened to the main tent at the 22nd Street Show.
 

Tables were pack with "lots of things."

What would the 22nd Street Show be without carved cephalopods, amethyst cathedrals, and beads?

My observations about the mini-Tucson event: 1) I was only in town long enough for a quick visit to two venues; 2) the buyers at Mineral City seemed serious and were looking for minerals, and perhaps a few supplies; therefore, the crowd seemed small; 3) 22^nd Street dealers sell a variety of items, especially jewelry and loose stones/cabs/beads/slabs, with actual rough mineral specimens making up a minor amount.  During my visit, the tent was  frequented by many visitors (all seemed to be buying); 4) the Mineral City area will continue to grow with some dealers establishing semi-permanent shops (so I hear); 5) I thought the mini-Tucson was a success, especially after early cancellations and then getting permission to reschedule in April.  There was a shortage of international dealers but that was expected.  I certainly spent an enjoyable two days--at my age something that I treasure :)

Palo Verde trees (Parkinsonia sp.) were in full bloom across southern Arizona.
 

 

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FUNKY LITTLE ROCK SHOPS WITH NIFTY MINERALS

 Get off the beaten path... If you want to find those mom-and-pop joints, those funky little places, just ask around.    Guy Fieri

Funky little rock shops where everyone wears a mask!

I often bemoan the fact that certain items are disappearing from the American roadside, things like drug stores with ice cream and shakes, general stores, non-chain hamburger stands, and especially “mom and pop” rock/mineral/fossil stores.  I suppose that my age and nostalgic thinking make these disappearances seem severe when in reality you can order any mineral that pops into your mind from a web business (now ice cream is a little tougher).  But there is, to me, something special about pulling open a dusty drawer in an old cabinet and taking a lighted loupe to examine a dusty specimen with old hand-written labels.  I am always on the lookout for these stores and make an attempt to locate and patronize these establishments.  On the other hand, it is tough to make a living selling minerals for a buck or five and most of these stores seem a labor of love.

I recently took a little road trip and stopped at one of my favorite old timey stores and begin sneezing while blowing dust off some of the drawer specimens—not many other tourist patrons bother with the drawers.  Not really needing any new minerals, I still made a purchase of some interesting specimens at “cheap” prices.  So, what little jewels did I come home with (only a partial list)?

The very reason I collect and write about minerals is so I might not sleepwalk through my entire life.    Apologies to Zadie Smith

Bisbee, Arizona, is known to rockhounds and mineralogists through the world.  The Copper Queen Mine and the Lavender Pit Mine have produced an array of secondary copper minerals that are considered classics.  Rock and mineral shows have devoted their attention and themes to Bisbee minerals.  And virtually any mineral collection, at least here in the states has a beautiful specimen of blue Bisbee azurite and usually one of green malachite.  However, I needed something new from Bisbee and spotted a thumbnail with antlerite, a copper sulfate hydroxide [Cu₃(SO₄)(OH)₄].  Antlerite is found as a secondary mineral in the carbonate-poor, oxidized zone at many copper mines but is never common.  In fact, Anthony and others (1995) noted it was rare and in mines of the Bisbee area was collected from the Copper Queen Mine (probably) as small crystals of excellent quality implanted on brochantite.  Antlerite ranges from emerald-green to light green to blackish green in color.  Crystals are vitreous, translucent, brittle and soft (~3.5 Mohs) and leave a pale green streak.  Most crystals are thick tabular, or equant or short prismatic.   They also occur as rather non-descript granules or aggregates of fibrous crystals.

Green crystals of antlerite of various and shape.  Some of the very light green translucent mineral matter may be brochantite.  Width FOV ~4 mm. 

A garnet was one of the standard minerals included in Physical Geology laboratories specimen boxes (along with feldspar, calcite, quartz, etc). Usually, it was a dark colored dodecahedron that was identified by its shape and hardness of ~6+. Students learned that garnets were silicates and created during a metamorphic event.  

By the time mineralogy class rolled around students were introduced to a variety of garnets and learned that “garnet” was not a legitimate mineral name but referred to a group of silicate minerals differing in composition but crystallizing in the same system (Isometric), and their mineral properties such as hardness, cleavage and density were all very similar. Usually the specimens studied were almandine [Fe²⁺₃Al₂(SiO₄)₃], pyrope [Mg₃Al₂(SiO₄)₃], spessartine [Mn²⁺₃Al₂(SiO₄)₃], andradite [Ca₃Fe³⁺₂(SiO₄)₃], and grossular [Ca₃Al₂(SiO₄)₃]—all end members in the Garnet Group.  Things got more difficult in graduate-level courses in igneous and metamorphic mineralogy/petrology and instructors added uvarovite, also an end member, [Ca₃Cr₂(SiO₄)₃] to the list for study. Chemical formulae for members of the Garnet Group is X₃Y₂Si₃O₁₂ where X includes the divalent (2+) oxidation charge cations like Ca, Mg, Fe, and Mn while Y represents trivalent cations (3+) oxidation charge like Al, Fe, and Cr; all cations are clustered around the silica tetrahedra. Today MinDat lists 14 different minerals belonging to the Garnet Group with many of these types having numerous varieties. For example, spessartine has at least six varieties while grossular parades out 15 varieties including the popular, and expensive, green tsavorite with coloring supplied by chromium and vanadium. Garnet Group members have two solid solution series: 1) pyrope-almandine-spessartine; and 2) uvarovite-grossular-andradite. Essentially all colors of the rainbow are present in some variety of garnet since rare blue colored specimens were discovered a couple of decades ago.

At the rock/mineral shop I picked up a small cluster of andradite crystals. This species has three major varieties: melanite (black), topazolite (yellow-green), and the uber expensive demantoid (green).  My find of mineral store garnet crystals is the rather unusual andradite variety termed melanite or titanium garnet.  These are black garnets where the titanium evidently replaced or comingled with the silicon since the titanium (up to ~11%) appears as titanium oxide.  The crystals are dodecahedrons with an adamantine luster and a hardness of ~6.5-7.0 (Mohs), and a white streak.  They are pretty opaque but will partially transmit light from a rear source. Unlike other garnets that usually form in metamorphic environments, melanites with their titanium often form in alkaline igneous rocks (low silica), but also in serpentine, skarns, crystalline schists, and iron ores. The locality information, simply “New Idria Mining District, San Benito, CO, California.”  This District is famous for world class benitoite, neptunite, topazolite and melanite andradite garnets. I believe the garnets formed in a skarn, a metamorphosed limestone intruded by hydrothermal solutions heated by nearby intrusions.

Titanium-rich andradite crystals, variety malanite.  Width FOV Top: ~2.1 cm.; Bottom: ~7 mm.

The Spruce Pine Mining District in North Carolina is one of the best-known mining areas in the U.S.  It is in a beautiful area of the Blue Ridge Mountains centered in Mitchell and Yancy Counties and mineral-wise is famous for gem specimens of beryl--varieties aquamarine, emerald, heliodor, and morganite.  North Carolina is the country’s largest producer of feldspar and original mines centered near Spruce Pine and produced from a Precambrian pegmatite; however, current production is from “alaskite” (a variety of granite) described as a very “coarse-grained, light-colored, feldspar-quartz-muscovite rock. Composition of the rocks averages about 40 percent plagioclase (soda-spar), 25 percent quartz, 20 percent microcline (potash-spar), and 15 percent muscovite” (information gleaned from North Carolina Geological Survey at deq.nc.gov).  The Spruce Pine area is also the major producer of sheet mica, scrap mice and olivine in the U.S., as well as a number of other industrial minerals. 

The specimen I picked up is an intrusive igneous rock with various feldspars, schorl (a black tourmaline), quartz, and a nice golden beryl crystal that was collected from the Ray Mica Mine near Burnsville in Yancy County. I have been through Burnsville a few times on my way to lodging in Little Switzerland, and while traveling along the Blue Ridge Parkway, a scenic 469-mile road running near the crest of the Blue Ridge and connecting Great Smoky Mountain National Park in the South and Shenandoah National Park in the north.  The Blue Ridge is the high part of the Appalachian Mountains with a variety of crystalline rocks emplaced during continental collision and subduction generally termed the Grenville Orogeny or the Grenville Cycle.  At any rate, the Grenville was not one major event but a series of orogenic phases from ~1250 Ma to ~980 Ma, or somewhere around there, with the end result being the formation of the Supercontinent Rodinia.  There were additional granite emplacements somewhere around 700 Ma due to rifting of Rodinia.  The Paleozoic history of the Blue Ridge and the Appalachian Mountains is a “whole nother story.” 

Golden beryl. Top: length ~1.6 cm.; width of hexagonal end ~7 mm.  

Cluster of schorl crystals.  Width FOV ~1.9 cm.

I enjoy it; my experiences in traveling and looking at the rocks have taught me the importance of an open mind and have given me a willingness to wander off the beaten path - not only to keep life interesting, but also to understand in a meaningful way that things do not look the same from every vantage point.               

Apologies to Esther Dyson

REFERENCES CITED

Anthony, J.W., S.A. Williams, R.A. Bideau, and R.W. Grant, 1995, Mineralogy of Arizona: The University of Arizona Press, Tucson.

JACKSTRAWS, CERUSSITE AND ATLAS MISSLES: I"M READY FOR THE TIMES TO GET BETTER

 

Life in the fast lane in Tescott, ca. early 1950s.  Life was good.

As a kid growing up in rural 1940s-50s Kansas “the boys” essentially had the run of the town and created their own “fun.”  No electronic games, no TV, and not much money in the families.  But virtually everyone in town was on the same level and my brothers and I really did not notice much of a socio-economic difference in the population of maybe 396 (that is a stretch), plus numerous dogs, only a few cats (no dog was a “house pet” and they all loved to chase cats), and one yellow canary who laid eggs and pined for a mate. We knew the local bankers had more monetary resources than most, but on the other hand, my family was able to borrow money to keep my father’s business above water. Well, not always above water since the town usually flooded about every five years (and still does).  I always thought the village was a Ford and Chevy (always used vehicles) town with a scattered Mercury or Plymouth and an occasional Hudson, Packard or Studebaker thrown in the mix.  In other words, a non-wealthy small town much like the others in rural farm/ranch Kansas.  Most families had provided a father and/or a brother to World War II and Gold Star mothers proudly hung the medallion in the front window (and grieved for the remainder of their lives). Korea sort of came and went (for a kid) but I do remember the WWII vets talking about the “commie reds” trying to take over the world.  At 10 years old I was too busy climbing trees, swimming in the local ponds, fishing, and trying to blow things up with firecracker powder to think much about the “commies.”

I've got to tell you I've been rackin' my brain

Hopin' to find a way out

I've had enough of this continual rain (substitute any word--shooting, war, virus)

Changes are comin', no doubt

It's been a too long time

With no peace of mind

And I'm ready for the times

To get better

                                                                        Crystal Gayle

I think if you question persons of my age and ask what changed their life as they lost their carefree “kidhood” and moved to adulthood, they will answer “Vietnam.”  I have prefaced numerous other Blog postings about my childhood and college days and will not repeat them.  However, my change was almost immediate—the day they moved the giant Atlas Missile down the highway to a large hole in the ground about a mile from town (Operational Base #10 assigned to 550^th Strategic Missile Squadron).  I thought, wow, maybe those “commie reds” really want to “kill us.”  I dreamed about some guy in the Kremlin with a map and a red pin stuck into Tescott, Kansas, noting a hole in the ground there housed a really big missile.  I feared that if those Kremlin boys pushed a button the people in Tescott did not have much of a chance.  I also wondered where our big Atlas was pointed.  Was it aimed at Moscow, or perhaps at a podunk small, rural town in Siberia? Dad didn’t know the answer; however, he was also worried.  And then it all hit, Cuba, eastern Europe, and some unknown jungle in southeast Asia called Vietnam or French Indochina.  Our country is still suffering the effects of that jungle today.  Will it ever go away?  By the way, that ole hole in the ground is still in the pasture covered with some big steel doors—at least that is the rumor.  I think there were 12 of these missile silos surrounding a Strategic Air Command (SAC) base at Salina.

Yesterday is not ours to recover, but tomorrow is ours to win or lose.    Lyndon Johnson

Now, how do all these rattling words connect to geology?  It has been a long story, but I am getting there. As I noted, kids in my small town did not have electronic gizmos to play with and our games were pretty simple—dominos, board games like Monopoly (not my favorite), building “things” with Tinkertoys or Lincoln Logs, and something called Pick-up-sticks or Jackstraws.  If you can imagine a number, 50 or so, of ~9-inch-long colored toothpicks that are held in a “bunch” with one end touching the floor, and then gently released to form a “pile” of sticks, you have the basics of the game!!! Participants tried to remove a single stick without disturbing the others.  Big clumsy hands like mine were not overly successful and my final count was usually low.

I suppose that today’s children would be quite bored with the game—I was!  Jackstraws takes its name from the straws in a scarecrow or child’s doll—individual straws going in many different directions.

In rockhounding and mineralogy the name jackstraw is now applied to long prismatic crystals of several different minerals that appear in sprays or masses in which individual crystals are haphazardly arranged in “every which direction”—a jackstraw aggregate of crystals.  Among the best-known Jackstraw Crystals are orange-red crocoite from the Adelaide Mine, Tasmania, millerite from Halls Gap, Kentucky, stibnite and tourmaline group minerals from a variety of locations, and epidote from the Green Monster Mine, Alaska. However, to most rockhounds the descriptor jackstraw brings up connotations of cerussite from the Flux Mine, Santa Cruz County, Arizona.

Jackstraw cerusssite on limonite/goethite (iron oxide) matrix.  Width FOV Top: 1.2 cm.; Middle: 9 mm.; Bottom: 7 mm. 

Interestingly the Mine is very near Alum Gulch in the Patagonia Mountains, the area that produced halotrichite described in the Posting July 24, 2020. The Flux, at one time, produced copper, lead, zinc silver, manganese, and minor gold from a complex of Paleozoic rocks intruded by Mesozoic igneous rocks, and a Tertiary rhyolite.  I believe most of the mineralization is associated with intrusive dikes and sills connected with both the granite and the rhyolite.  Small scale mining was present in the middle 1800s while larger production centered on 1884-1993.  Claims and ownership have been sort of haphazard since the end of large-scale mining in 1963 and active claims are still present.

The major mineral commodities from the Flux were zinc and lead with the latter entering into the jackstraw picture.  Cerussite is a secondary lead carbonate [PbCO₃] most often associated with primary galena [lead sulfide] and anglesite [lead sulfate].  In most instances the galena [PbS] oxidizes to anglesite [PbSO₄] and then to cerussite [PbCO₃] with exposure to carbonated water.

Cerussite, or white lead ore, has a variety of crystal habits including massive, reticulate, tabular, thin plates, equant, fibrous, prismatic, and others.  The colors are also varied but are mostly colorless and pale pastels and all leave a white streak.  The hardness is ~3.5 while crystals have a greasy to adamantine luster, a conchoidal fracture, and are translucent to transparent.  Because of the lead content the mineral is “heavy” with a high specific gravity (~6.5).  As a carbonate, cerussite will “fizz” in weak hydrochloric acid

The Jackstraw crystals from the Flux Mind are snow white in color and form spiky brittle crystals or very tight parallel bundles in a limonite/goethite matrix. Why do these jackstraw crystals form? I don’t have the slightest idea why. That is one of life’s persistent questions that always are better described than easy answers.

Jackstraw cerussite or the game of Jackstraws is not to be confused with the song Jack Straw by the Grateful Dead!!!

Leavin' Texas, fourth day of July,
Sun so hot, the clouds so low, the eagles filled the sky.
Catch the Detroit Lightnin' out of Sante Fe,
The Great Northern out of Cheyenne, from sea to shining sea.

MORE PESKY MONT SAINT-HILAIRE MINERALS

 Every day brings new choices.          Martha Beck

The previous posting described, sort of, a few sodium-rich minerals from the Poudrette Quarry located on Mont Saint-Hilaire near Montreal Canada.  The area has some very uncommon alkaline-rich igneous rocks that produce a suite of very rare to uncommon minerals. Since I am working with purchased and gifted micromounts, the mineral crystals in the mounts are quite small (many less than one millimeter) and often (most of the time) very difficult for me to identify; however, I am giving it my best to understand as much as possible. 

In youth we learn; in age we understand. Marie von Ebner-Eschenbach

Lorenzenite is a sodium titanium silicate [Na₂Ti₂(Si₂O₆)O₃] that is usually associated with alkaline magmatic or pegmatitic rocks rich in nepheline and deficient in quartz. The Type Locality of lorenzenite is not at Mont Saint-Hilaire but at another famous outcrop of nepheline syenite pegmatite, the Narssârssuk pegmatite, Narsaarsuk Plateau, Igaliku, Kujalleq, Greenland.  As at Mont Saint-Hilaire, the Greenland pegmatite has produced a number (13) of Type Locality minerals rich in sodium (including elpidite described in the previous posting). I find it interesting that MinDat does not have a photograph of lorenzenite from its Type Locality.

Lorenzenite from the Poudrette Quarry usually appears as acicular needle-like crystals often in sprays (seems to be an atypical habit).  Most are relatively colorless and are transparent to translucent.  However, these Canadian crystals are completely different from large equant and opaque crystals appearing in various darker shades of brown, mauve, blue, and black from localities in the Kola Peninsula in Russia (825 minerals and 248 Types; see posting Nov. 24, 2019) .  Lorenzenite has a hardness of ~6.0 (Mohs) with Poudrette crystals being vitreous to subvitreous while Russian specimens are dull to submetallic.  Poudrette crystals fluoresce a pale yellow to dull green under short-wave ultraviolet light and was a big help in identifying crystals on my specimen. 

Sprays of lorenzenite with a variety of other minerals that remain beyond my reach of identification.  The scattered black crystals in the upper left are submillimeter crystals of anatase, a titanium oxide. Width FOV ~1.0 cm.

Scattered anatase crystals as noted above.
 
 

An enlargement of lorenzenite from above photomicrograph.

Polylithionite is a member of the “Mica Group” and more specifically the Trioctahedral Micas, a family that includes minerals such ass biotite, lepidolite, zinnwaldite, and phlogopite—all silicates where the major cations are potassium or sodium, plus aluminum, magnesium, lithium, iron and perhaps a few others. Polylithionite is a potassium lithium-rich mica [KLi₂(Si₄O₁₀)(F,OH)₂]: Poly=many, Lith=lithium, so much lithium. It is found in alkaline igneous rocks with the mineral Type Locality in a pegmatite exposure, the Ilímaussaq complex, Kujalleq, Greenland (with 11Type Minerals).

Polylithionite crystals show a hexagonal outline and appear to be hexagonal crystals composed of stacked sheets (perfect basal cleavage).  However, they are actually pseudo hexagonal crystals that are colorless, white, gray, violet, or pinkish. All colors are transparent, soft (Mohs 2-3) and have a pearly luster with a white streak. The crystals, mostly tabular, also fluoresce yellow. There is a solid solution relationship between polylithionite, lepidolite, and trilithionite (minerals are determined by the lithium-aluminum ratio). 

 

Crystals of micacous, hexagonal polylihionite embedded in crystals of natrolite.   Width FOV ~1.3 CM.    

Glassy translucent to transparent prismatic crystals of natrolite, some with shallow pyramidal termination. The longest crystals are ~3 mm.

Another sodium aluminum silicate, natrolite, shares my thumbnail  specimen with polylithionite.  Natrolite [Na₂Al₂Si₃O10-2H₂O] is a zeolite and more often is found in miarolitic cavities of basalt.  It is related to scolecite (calcium aluminum silicate) and mesolite (sodium calcium silicate) and very difficult for an ole duffer like me to distinguish. Most natrolite specimens for sale at mineral shows or exhibited in museums are long, slender, prismatic, vitreous crystals up to a meter in length.  The Poudrette natrolite crystals are “square shaped along the long C-Axis”, “short” (squat) prismatic crystals rather than needle-like. They have a very shallow pyramidal termination, are translucent to transparent with a measured hardness of ~5.0-5.5. Colors of all crystals range from colorless, white, gray, even to colorful shades of orange, pink, brown to green. As for the environment of formation, MinDat.org states: “[Natrolite crystals] characteristically [are] found in low temperature hydrothermal systems, especially in volcanic and volcanically-derived rocks, but also in a wide range of other rock types, typically feldspathic [like the nepheline syenite found at Mont Saint-Hilaire].” At any rate, the specimen is quite interesting and likely contains other minerals that I cannot identify—above my pay grade.

There is no end to education. It is not that you read a book, pass an examination, and finish with education. The whole of life, from the moment you are born to the moment you die, is a process of learning.          Jiddu Krishnamurti

I have a third specimen labeled serandite which is a sodium manganese silicate [NaMn₂Si₃O₈(OH)].  Mont Saint-Hilaire is famous for producing salmon-orange to salmon-red crystals of serandite with the color, due to manganese, making the mineral somewhat easy to identify.  However, some serandite crystals tend toward brown to pink to colorless and there is a good possibility that the pink crystals are schizolite (sodium calcium manganese silicate). In addition, most of the Poudrette crystals are long prismatic and sometimes bladed.  I studied my thumbnail for what seem like hours trying to locate the distinctive deep salmon-red, long crystals I had seen in professional exhibits—no luck.  In digging into the literature, and examining many photographs, I discovered that some serandite crystals are short, blocky. prismatic crystals, sometimes colorless to light peach/salmon. In opening my mind, I soon “discovered” a nice grouping on my specimen. Serandite crystals are transparent to translucent, have a vitreous to greasy luster, a white streak, and a hardness of 5.0-5.5 (Mohs).  At Mont Saint-Hilaire serandite crystals are found in a sodalite syenite pegmatite composed mainly of microcline, sodalite, and nepheline (Lacroix, 1931in Tarassoff and Horvath, 2019).   For a great history and description of serandite see the Tarassoff and Horvath article.

 

These light peach/salmon crystals are my identification of serandite. I could be wrong.  The longest dimension of any of the crystals is ~ 2mm.

The joy of life comes from our encounters with new experiences, and hence there is no greater joy than to have an endlessly changing horizon, for each day to have a new and different sun.            Christopher McCandless
 

REFERENCES CITED

Tarassoff, P. and L. Horvath, 2019, Connoisseur’s Choice: Serandite, Mont Saint-Hilaire, Monteregie, Quebec, Canada: Rocks and Minerals, vol. 94, issue 4. 

This has been a tedious exercise for me.  I am not a mineralogist, the minerals are tiny and numerous from Mont Saint-Hilaire, most are unfamiliar to me, my digital camera ate several photomicrographs (about 3 times), and I miss my desk computer (this has been completed on a laptop).  But right or wrong the editor said it is going to press!  And the sun is shining, I am safe and well, and my entire family has now received at least the first vax.

The search for knowledge is a long and difficult task.    Fabiola Gianotti