Sunday, November 1, 2020

LEAD OXIDE (MINIUM), WITCHES, PUMPKINS, BLUE FULL MOONS, AND A HEADLESS HORSEMEN

 

On mounting a rising ground, which brought the figure of his fellow-traveler in relief against the sky, gigantic in height, and muffled in a cloak, Ichabod was horror-struck on perceiving that he was headless! – but his horror was still more increased on observing that the head, which should have rested on his shoulders, was carried before him on the pommel of his saddle!   Washington Irving

It that time of year again—the Autumn season with falling leaves ( I have raked the red maples seven times this year with only the sugar maple yet holding a few leaves), a crisp coolness in the evenings and mornings, a passing snowstorm or two, finally freezing the flowers enough that sheet covers are worthless, the honking of squadrons of geese and the trumpeting of a sedge of Sandhill Cranes heading south on the winds of a cold front, the strutting of city slicker deer, the bugling of elk in the high country, the clanging of male big horn sheep as they follow an ancient mating ritual, and the bright orange color of pumpkins in a patch. 

I’m so glad I live in a world where there are Octobers.      L.M. Montgomery

 

Today's hybrid pumpkins do not resemble pumpkins from the past.  From the field of Farmer Ron.

For the farmers in my boyhood hometown area of central Kansas fall was a time of picking corn or making silage for the large, tall, circular silos dotting the countryside. My first farm job, before I could drive my uncle’s tractor (5th grade), was walking through picked corn fields and nabbing ears that the picker missed—up and down and up and down the rows I went.  A few years later I was driving a truck along side the silage grinder catching the ground up corn spraying into the truck—"pay attention Mike,” my uncle would yell.  “Just keep a steady speed.”  When the truck was full, I was replaced by another worker pulling a trailer and I would head to the silo and dump the silage into an elevator that would blow it into the silo.  I don’t know the exact chemical changes taking place but the silage sort of mellowed as it underwent anaerobic fermentation and converted sugars to acids.  During the winter months one had to climb the ladder, open a port, get inside the silo and throw out forkfuls of silage into a truck bed below and then “go feed the cattle.” Lots of hard work. There is a reason I headed off to college and became a geologist!! 

A Kansas silo and abandoned windmill.  Photo courtesy of Modern Vespa.

My mother told me that as a young girl, farmers arranged parties with participants husking corn.  The kids were in a circle drinking cider and eating popcorn and husking dried corn.  When someone husked a cob that had colored kernels (“Indian Corn”—no hybrids back then) he or she could kiss the person of their choice! This activity served to help the farmer get his corn husked and was a social opportunity for the teens.

In other instances, families gathered to make molasses, a fascinating process to watch.  Modern day molasses is made as a byproduct of sugar cane refining.  Decades ago, some farmers planted an acre or so of sweet sorghum.  Sorghum is a tall grass that can be used for cattle feed, either cut and baled or ground as silage. The sweet sorghum was hand cut and transported to a farmer who had a crushing mill where it joined the product of other farmers. It was run through the mill with the juice saved and added to a large, really large, pot and slowly cooked on an open fire until about 10%  remained (is black and syrupy) when it is poured into jars and canned in hot water. Up until the early 20th century molasses was the major sweetener for American families.  In one particular instance the farmer used a horse walking in continuous circles to power the crushing mills. The late afternoon was usually capped off with a picnic (possibly with chokecherry wine if farmers were Lutherans, soft drinks if it was a Methodist event). I still enjoy molasses, especially when used in cookies!


Making molasses the old fashioned way.  Photo courtesy of  chloesblog.bigmill.com/

I think a person has to believe in something or search out some kind of faith; otherwise life is empty, nothing. How can you live not knowing why the cranes fly, why children are born, why there are stars in the sky. Either you know why you live, or it's all small, unnecessary bits.     Sarah Ruhl

What more could one ask for than Autumn?  I know—a special holiday celebrated on the last day of October, one of the special days even at my age.  Halloween ranked just after Christmas when I was a kid running around a small central Kansas town. There is a child in every one of us who is still a trick-or-treater looking for a brightly-lit front porch (Robert Brault). We looked forward to the day when every young boy in town dressed up like a hobo and the girls were in the princess mode.  Our parents certainly did not have money for a purchased costume, so we cobbled together something from a rag bag and on the good years we had a new mask.  My mother always said, “Mike what do you want to be this Halloween?”  I replied, “how about a Viking this year with a red wig and a real sword. Well,” she replied, “maybe you could go as a hobo.” So, I went as a hobo around town collecting candy, apples, and other goodies.  We always hit our back-neighbor’s home for Myrtle gave us popcorn balls.  Mrs. Jones down by the railroad tracks had Baby Ruth candy cars while “Ole Lady Jackson” doled out Butterfinger bars.  Mostly we avoided “mean Jack” since his prize was a single piece of chewing gum.  And so, it went.  I was always a firm believer in the old saying, During the day, I don’t believe in ghosts. At night, I’m a little more open-minded. It was nice to return home with the goodies, for mom usually had hot chocolate and popcorn ready for us. We stuffed ourselves and mostly received a “stomachache” for our efforts. 

Nothing on Earth so beautiful as the final haul on Halloween night.   Steve Almond

We knew that Halloween was a time for vampires, ghouls, ghosts, werewolves, zombies, and other creatures of the night. Besides the trick-or-treating, I remember town-wide bonfires or “wienie roasts” with marshmallows and telling scary stories usually involving someone losing their noggin,  having a Jack-o’-Lantern carving contest, with the older kids sneaking off to play a few pranks like outhouse tipping. As we got to the “girls discover boys” stage there were often costume parties with soft apple cider and apple bobbing.  Parents were in the outer circle of the fire often with some hard apple cider or my father’s specialty, chokecherry wine (lush, unctuous ripe fruit with a light touch of battery acid).  Wine Spectator gave it a strong 3/100).

When the witches go riding, and black cats are seen, the moon laughs and whispers ’tis near Halloween.  

What all this means is that in small town, post-War through the 1950s, America Halloween was a fun time for kids and adults alike. Men had come home from Europe or the Pacific wanting nothing more than a job, a home, a spouse, and children, well maybe a dance on Saturday night. Males would talk about duck hunting or farming (or chokecherry wine) while moms were bragging on their vegetable and fruit canning labors.  The old men were on lawn chairs complaining about their hemorrhoids, or “piles” as they called them, and remembering the days they shot 25 ducks for the “missus” and her sisters. As a disclaimer, and an important note, these remembrances are from a kid growing up in the plains of rural America.  A land that was settled mostly by northern European immigrants, Caucasians who held a grudge against Native Americans.  Cultural and racial diversity was nonexistent.  Most younger persons today would look back with disgust and call the entire life arrangement sexist, racist, and disgusting (women work, men drink wine, kids run wild); however, that was life 70 years ago.  Perhaps it was wrong and too much like Beaver Cleaver, but I can guarantee that my parents worked hard and raised children to the very best of their ability (Mom, Happy Halloween 107th Birthday).  But as a kid I always had a fantastic time and never even uttered the word sexist (or any of its derivatives).

Shadows of a thousand years rise again unseen. Voices whisper in the trees, Tonight is Halloween!       Dexter Kozen

As a kid, little did we know that Halloween had something to do with the dearly departed and was a serious Christian liturgical celebration.  In many/most Christian cultures November 1st is celebrated as All Saint’s Day or All Hallows’ Day and November 2nd as All Souls’ Day.  Most Christian holidays start the vigil with a feast the night before—All Hallows’ Eve became Halloween.  Early Christian churches sent criers into the street dressed in black cloaks ringing bells to remember the departed.  This probably morphed into costumes of the secular Halloween.  Soul cakes were baked and shared.  The kiddies would go house to house asking for soul cakes in return for praying for the dead.  Again, this practice morphed into “give me a treat or I will play a trick” on you.  Somewhere the praying for the dead disappeared.  However, in some countries All Saints’ Day and All Hallows’ Eve is serious business as people visit cemeteries and leave soul cakes and candles for the departed.  They then light large bonfires to guide the souls of the departed back to their earthly homes.  In my hometown we lite bonfires to roast “wienies” but perhaps some of the departed did return for a marshmallow. 

Painting of various saints by Fra Angelico, an Italian painter of the Early Renaissance, Public Domain photo.

What could make Halloween 2020 better (I know, I know, the election being over and Covid-19 eradicated but that ain’t goin to happen) but what will happen is that on Halloween 2020 there will be a Full Blue Moon.  We all know what a full moon is—big, bright, orb even seeming larger as it pops over the eastern horizon (due to an optical illusion). OK! A Blue Moon is a second full moon in a month, not an extremely rare feature, but still uncommon happening about every two and a half years.  The 2020 full moon on Halloween is a really rare event as there has not been a full moon on Halloween in all U.S Time Zones since 1944. Take the Moon sight in as the next is scheduled for 2039.  We should also realize that every full moon that does appear on Halloween is a Blue Moon since the days in the Gregorian Calendar are 30 or 31 days in length except February.  Moon cycles are 29.5 days in length.

The Harvest Moon glows round and bold, in pumpkin shades outlined in gold, illuminating eerie forms, unnatural as a candied corn. Beware what dare crawls up your sleeve, for 'tis the night called Hallows Eve.        Richelle Goodrich

We associate two colors with Halloween—black and orange.  Black is the color of death and children were often afraid of older women and associated then with black clothes (often mourning clothes) and assumed they might be a witch.  Actually, the word witch comes from the Olde English word wicce meaning wise woman.  I am uncertain where our perception of witches changed from wise woman to someone who could cast a nasty spell on you.  Probably during a pandemic when we needed to blame something or someone on our troubles—today we could try China?    Modern witches are usually associated with the Wiccans and their religion.  However, in olden times one would not want to be accused of witchcraft in Salem, Massachusetts.  As a kid I was certain that some older women in my hometown were nasty witches, or at least they had magic and were to be avoided.  The last thing a kid needed was a spell cast on him—that is one reason we carried toads in our pockets (that and to scare the girls).


The witches fly across the sky, The owls go, Who? Who? Who? The black cats yowl And green ghosts howl, Scary Halloween to you!     Nina Walter

And speaking of orange color, what about Jack-o’-Lanterns?  As far as I can tell, the  Jack-o’-Lantern tradition comes from an old Celtic tale that  recounts the experience of one Jack, a parsimonious fellow who managed to trick the Devil. As a result, ole Jack was forbidden entrance into either Heaven or Hell and was instead condemned to wander the Earth—waving his lantern to lead other people away from their paths. A wandering ghoul if you wish.

Oh!—fruit loved of boyhood!—the old days recalling,

When wood-grapes were purpling and brown nuts were falling!

When wild, ugly faces we carved in its skin,

Glaring out through the dark with a candle within!   John Greenleaf Whitter

In Great Britain, Jack-o’-Lanterns were traditionally carved from turnips. When the practice reached America, where turnips were much more expensive, cheaper pumpkins were used instead.  In rural Kansas boys sometimes used turnips since farmers often grew them as a fall crop to feed the porkers, or to serve as a substitute for potatoes (I actually like turnips, both raw and cooked).  However, turnips are hard, solid, and tough to carve so we used—wild growing Buffalo Gourds.  These aromatic (stinky) baseball to softball size fruits (Pumpkin Family) grew on vines and developed a hardened outer shell with a hollow interior when dry.  They are not nearly as “cute” looking as the numerous ornamental hybrid forms grown today. But they held a cheap little candle and served as a mini globe.  Kiddie ghouls could then march around with a globe in one hand and shaking a ghoulish rattle ( a gourd with either the dry seeds, or a few pieces of sand/gravel) in the other hand.  The light and the noise served to scare off the bad ghosts and witches.  It was also a tradition to use an actual craved pumpkin Jack-o’-Lantern with a candle as a talisman on the front porch or windowsill to ward away evil spirits.  I always thought that the more Jack-o’-Lanterns we carved the less pumpkins I had to eat (yes, I dislike pumpkin of any sort including soup or pie).

Buffalo Gourd.  Photo courtesy of Kimberly Kline.
  

May Jack-o-lanterns burning bright, Of soft and golden hue, Pierce through the future's veil and show, What fate now holds for you?     Jerry Smith 

Since this is a geology blog, mostly, I need to add some material about a mineral, so let me pick an orange one to signal my endurance in this time of self-quarantine. Pure orange minerals are tougher to find than say black, red, or blue varieties!  But, I have found one in my collection—minium, a lead oxide [Pb3O4]. It may also be red; however, I chose the orange variety.

Minium is actually a mixed valence compound with both Pb++ and Pb++++ in a 2:1 ratio—Pb++2Pb++++O4.  Since specimens of minium are mostly red in color it obtained the name red lead and has been used in paint pigments for millennia, especially in the Middle Ages. However, this pigment was mostly made rather than mined! White lead, cerussite or lead carbonate, was roasted in air until it turned yellow and then orange or orange-red  It is toxic to humans if ingested since: 1) it is not soluble in water; but 2) is soluble in stomach hydrochloric acid!

Mimium from Santa Fe Mine, Bala nos Muncipality, Balanos, Mexico. Width FOV 1.7 cm.

Minium is an earthy mineral occurring in small masses as a secondary mineral in lead deposits that have been highly oxidized.  It is found in a number of localities around the world but never in large amounts at any one locality.

Minium is soft at ~2.5 (Mohs), opaque, earthy to massive habit, it may be striated if you can find a cleavage face.  Some specimens, especially those bright red, have a shinier luster and are translucent.  The streak is an orange-yellow color.  Not much else I can say about minium.

I hope your Halloween is fun and spooky. Eat, drink and be scary!  I wish for a day full of peace, joy, and divine blessings for you and wish you a Happy All Saints Day. Let the beauty of the Full Moon inspire us to bring a change in our lives. Let it motivate us to keep moving ahead to achieve our goals. Wishing you a bright and Happy Full Moon Day my friends.

Thursday, October 29, 2020

THE BLUE IRON MAGNESIUM PHOSPHATES: SCORZALITE AND LAZULITE


It was a beautiful bright autumn day, with air like cider and a sky so blue you could drown in it.   Diana Gabaldon 

Some of my Blog readers know that I am partial to blue minerals, and to phosphate minerals.  And if the phosphate minerals are blue, that is even better.  Most of my minimal understanding of phosphates come from minerals found in Precambrian rocks of the Black Hills, and by conversations with Tom Loomis at Dakota Matrix.

Like many of the interesting phosphate minerals at localities around the world, the numerous pegmatites in the Black Hills produce most of the phosphate minerals. Perhaps the pegmatite most studied in the Hills is one exposed at the Tip Top Mine in the Custer Mining District. This former beryllium mine is the Type Locality for something like 12 colorful phosphate minerals and tens of others are mostly hidden away in vugs and fractures; most are microscopic, but all seem to have beautiful crystals.  I have written about several of these phosphates in this Blog.  A couple of years ago I had a personal tour of the Tip Top with noted mineralogist and mine owner, Tom Loomis.  I was looking for some of the tiny Tip Top phosphates but no luck—lots of triphylite and rockbridgeite but no nifty sprays of tiptopite!

A section of the Tip Top Pegmatite. near Custer, South Dakota.

Due to the Covid-19 pandemic I missed my fall trip to the Black Hills; however, I keep reading what geological information  I can acquire on both the Hills, and on phosphate minerals from other localities in the U. S.  One place that tweaked my interest was New Hampshire, home of several pegmatites along the west side of the state. I have had an opportunity to roam around New Hampshire enjoying the camping, mountains, and scenery, but that was in my soft rocks days and I was not really interested in mines and minerals.  So, I did not take the opportunity to explore the mines scattered around in the Grafton Pegmatite Field.  Like the Black Hills, the Grafton pegmatites are a hotbed for finding phosphate minerals, including the Palermo #1 pegmatite where something like 159 minerals, many of them phosphates, have been identified (MinDat.org).

Rather than feeling sorry for myself about the exile in the basement: I nabbed some coffee for my mug, pulled up my big boy pants, put a sparkle in my eye and a smile on my unshaven face, and decided that yep, I'm ready for the day.  Bring on the phosphates. 

So, I started rummaging around my collection during the constant self-quarantine time looking for phosphates to sort.  All phosphates have the PO4 anion with an oxidation state of 3- (phosphorus with a 5+ and  4 oxygens each with a 2- state leaves a total anion state of 3-).  Among rocks and minerals (to differentiate from chemically synthesized forms) primary phosphates crystalize from fluids in late stage magmatic crystallization, for example the mineral triphylite (a lithium iron phosphate). Secondary phosphates form many colorful specimens from the primary phosphates that are altered by aqueous solutions into minerals like strengite (hydrated iron phosphate). Sedimentary phosphates form at low temperatures from phosphorus-bearing organic material in ocean basins, epeiric seas, continental shelves and even a few fresh waters (see September 4, 2020 Post). Many of these organic phosphorites include large amounts of Apatite Group minerals.

What I came up with in my fumbling around was a specimen containing the blue, secondary phosphate, scorzalite, collected from the Palermo #1 Mine.  The Grafton Pegmatite Field, with the Palermo Pegmatites, is located in the Acadian Orogenic Belt, a tectonic area that represents the Devonian (~420Ma --~360 Ma) uplift of mountains in the northern section of the Appalachian Orogen, around southern Virginia to Newfoundland. This uplift was the result of plate movement as a microcontinent named Avalonia (parts of Europe) was banging against Laurentia (proto North America), and being accreted (the terrane was sticking to Laurentia) while the proto Atlantic Ocean was being subducted under the Laurentian continental plate. Of course, the orogenic event was much more complex that this explanation!  What we also know is that the active tectonic zone supplied magmatic plutons, volcanos, hydrothermal fluids, and lots of heat for metamorphic transformation of preexisting rocks.  I always had much respect for the New England geologists tromping through the vegetation and trying to decipher the stratigraphy and tectonic sequences, especially those early field workers who did not have knowledge of plate tectonics.


Cartoon x-section of events in the Acadian Orogeny, New England.  Sketch courtesy of Fichter and Baedke at http://csmgeo.csm.jmu.edu. 

In the above sketch, the Taconic rocks are roots of  Ordovician orogenic events where microcontinent(s) (generally referred to as Taconic Terrane)  banged into proto North America creating mountains and accretion.  The Acadian terrane is the Avalonia Microcontinent being shoved up and accreted to proto North America.  The Catskill rocks are a large clastic wedge of sediments shed off the rising Acadian Mountains.  The Acadian rocks (Avalon terrane) were instrumental in the early days of defining "Continental Drift."  By the Permian addition rocks and terranes had banged into, and stuck to, proto North America (the Alleghenian Orogeny) helping to create the Pangaea Supercontinent.  By the Triassic Pangaea was breaking apart and in proto North America the split sent part of the Avalon rocks with proto Europe and part stayed with North America.  Early geologists noted that some North American rocks were identical to European rocks and suggested that at one time they were connected and later "drifted" apart (Continental Drift).  At that time geologists did not understand the mechanism for "drifting."  Today we know much about plate tectonics and sea floor spreading.   

The pegmatites within the area of Palermo mines #1, #2, and #3 are quite complex but have as their primary phosphates triphylite (Li, Fe) AND/OR lithiophylite (Li, Mn), and montebrasite (Li, Al) AND/OR ambygonite (Li, Al, F) (Nizamoff, 2006).  These primary minerals then interacted with post-magmatic aqueous fluids to produce several tens of secondary phosphate minerals including scorzalite. Nizamoff (2006) also determined that primary montebrasite [LiAl(PO4)(OH,F)] and/or triphylite (lithium iron phosphate) PLUS muscovite (to add alumnium) were subjected to high temperatures, ~500oC—300oC,  by infusions of hydrothermal fluids.  These fluids also leached out lithium and fluorine and left behind iron, magnesium, aluminum, and hydroxyl ions and the result was the formation of the iron aluminum phosphate, scorzalite [FeAl2(PO4)2(OH)2], and/or its magnesium analogue, lazulite [MgAl2(PO4)2(OH)2]. So, the primary phosphates were heated by hot fluids which also leached out some of the elements and left behinds others producing the often colorful secondary phosphates.



Photomicrographs of blue scorzalite from the Palermo #1 Mine.  Width FOV top ~1.0 cm, middle and bottom ~ 9 mm.

Scorzalite has a blue color of some sort—blue-green, light blue, dark blue—but mostly a light sky blue with a resinous or subvitreous or even a dull luster.  It may appear something less than transparent but darker shades are opaque. The hardness is ~6.0 (Mohs) and specimens will produce a white streak. Crystals may be observed in some specimens; however, they are quite small.  Most specimens are granular or massive blue blotches.

As I noted above scorzalite [FeAl2(PO4)2(OH)2] has a magnesium analogue named lazulite [MgAl2(PO4)2(OH)2] and they are in a solid solution relationship. As best that I can tell lazulite is usually a darker blue color, at times a midnight blue, and has larger and better formed crystals.  I am unaware of intermediate minerals.


Two photomicrographs picking up the dark blue color of lazulite crystals, each has a maximum width of ~ 3 mm. Specimen from Rapid Creek, Yukon Territory, Canada.

 According to webmineral.com, the magnesium  and iron elements are shown below:

Molecular Weight = lazulite 302.23 gm    
Magnesium    8.04 %  Mg       
Aluminum    17.86 %  Al       
Phosphorus  20.50 %  P        
Hydrogen     0.67 %  H         
Oxygen      52.94 %  O               

Molecular Weight = scorzalite 325.88 gm
   Magnesium    1.86 %  Mg    
   Aluminum    16.56 %  Al   
   Iron        12.85 %  Fe   
   Phosphorus  19.01 %  P    
   Hydrogen     0.62 %  H     
   Oxygen      49.10 %  O

 

   

Pseudo-octahedral crystal of an iron manganese phosphate, perhaps  kryzhanovskite, a pseudomorph after phosphoferrite. Width specimen ~.75 cm.  

The specimen from Palermo #1 also held a bonus mineral that took me some time to identify--the iron manganese phosphate, phosphoferrite [(Fe,Mn)3(PO4)2-3H2O]. And boy was it a surprise--read on.  As noted, I had this nifty crystal pegged as phosphoferrite due to physical properties including those displayed in photographs.  Many specimens are some sort of a brown to reddish brown (the oxidized forms) to green colors and are transparent to translucent.  They belong to the Orthorhombic Crystal System and often occur as tabular to pseudo octahedral crystals.  They are soft at ~3.0+ (Mohs) with a vitreous to resinous luster.  The twist is that I continued to study the fantastic tome by Nizamoff, (2006) and could not locate his description of phosphoferrite in the Palermo #2 Mine (next door to #1).  Instead, he noted that Moore (1971) and Moore and others (1980) suggested that the mineral kryzhanovskite [(Fe,Mn)3(PO4)2(OH,H2O)3] may form from the oxidation of phosphoferrite. With this information Nizamoff  (2006) noted "it appears that at Palermo #2 phosphoferrite crystallized in the non-oxidizing assemblage with vivianite, ludlamite and fairfieldite group minerals and was subsequently oxidized to kryzhanovskite. Consequently in the observed assemblage at Palermo #2, kryzhanovskite has a pseudomorphic relationship with phosphoferrite."  


REFERENCES CITED 

Moore, P.B., 1971, The Fe2+3(H2O)n(PO4)2 homologous series: crystal-chemical relationships and oxidized equivalents: American Mineralogist, vol. 56.

Moore, P.B., T. Araki, and A.R. Kampf, A.R., 1980, Nomenclature of the phosphoferrite structure type: refinements of landesite and kryzhanovskite: Mineralogical Magazine, vol. 43.  

Nizamoff, J., 2006, The Mineralogy, Geochemistry and Phosphate Paragenesis of the Palermo #2 Pegmatite, North Groton, New Hampshire: University of New Orleans Theses and Dissertations. 398.

New Hampshire is one of the birthplaces of American freedom and independence - a place with a love and a passion for liberty. Marsha Blackburn