A FEW NIFTY MINERALS FROM CREEDE

 I am still rummaging around my mineral collection trying to sort out and check material after my move from Colorado to Wisconsin. But I am not very diligent with sorting through a large amount of material “tossed” into the garage. This latter mess does not include my minerals; therefore, the stuff is being re-thrown into two piles 1) why did I transport this material just to haul it to Goodwill; and 2) how do I find space for this “good” stuff? I guess these are some of life’s persistent questions so perhaps I should call in Guy Noir!

Sorting minerals is an enjoyable hobby as I try to come up with ideas on how to include them on this Blog. Today I am briefly noting three mineral specimens that are quite attractive but only cost about a buck each. That $3.50 total is about the price of a single black coffee at my local shop. The initial taste of the coffee is fantastic, but the enjoyment of the minerals is long lasting.In addition, I am throwing in a couple of other, slightly more expensive, specimens.

One of best-known mining areas in Colorado is Creede, located in the San Juan Mountains in the southwestern quadrant of the State. The mines of the area produced, starting in ~1891, a significant  amount of silver. The mine owners prospered for a couple of years but then the  Panic of 1893 hit like a bomb as the Sherman Silver Act was repealed that year. Many smaller and less productive silver mines at all locations in the country were shuttered due to lower prices for silver and costly production costs. However, the Creede mines utilized their massive silver-rich veins and lower production costs to survive the Panic and produce until 1985 when the Last Chance mine closed. But even today there are rumors of core drilling in the area as companies try to ferret out new productive veins.

Want to know about the Sherman Silver Act? Check post May 18, 2012

Creede is a booming community today—but only during the summer/fall months. Like the mythical Phoenix arising from the ashes and regenerating itself, Creede has made the journey from a typical western mining community with periods of boom and bust to a thriving “destination locality” that attracts thousands of visitors each year. The community has “boomed” due to the merging of their past silver history/wealth with an absolutely gorgeous physical setting at 8850 feet, a well designed underground mine tour, an underground  museum, well preserved Victorian buildings and timbered mining structures, art galleries, numerous cultural and social events such as a rock and mineral show, a scenic main street hemmed in by tall, 1000 feet, beds of rhyolite, and the presence of the Amethyst Vein that still produces great mineral specimens. However, the icing on the cake was the arrival, in 1997, of Jack Moris, a long-haul truck driver, and his dream of turning a mine or two into an immense geology attraction. So, off he went and purchased the Last Chance Mine situated along the Amethyst Vein, started specimen-collecting, both in the mine and in the dumps, and soon attracted hordes of rockhounds and tourists. Today, visitors can pay a very modest fee to collect in the dumps, take an educational underground mine tour (fully approved by the State), and purchase magnificent specimens in the gift shop. Old Creede, along with the ingenious Jack and his mine, has proved to be a spectacular tourist attraction, not only for rockhounds but for fans attending performances of the well-respected Creede Repertory Theater, the annual rock drilling competition, and the camping, off road and ATV trails, and nearby cold-water trout fisheries to provide a wealth of opportunities.

As a kid growing up in small town Kansas, I believed that we could see the mountains as soon as dad crossed the Kansas-Colorado state line on U.S. 40 heading to Denver. Today, more educated Kansas visitors to Colorado know you can’t spot Pikes Peak from I-70 but often believe that the State’s magnificent mountains formed about the same geological time during the Laramide Orogeny (AKA mountain building event). And it is true that the Laramide event greatly affected much of the western half of the State. I suppose it is too complicated to tell the kiddos that the elevation of the Front Range is due to a post Laramide regional uplift and accentuated by erosion.

However, the San Juan Mountains have their ancestor in the major volcanic event starting about 40 Ma when large magma domes begin pushing up and exploding, a massive ignimbrite flare-up across Utah, Colorado, and Utah in what must have been spectacular fashion. Many of these volcanoes and vents spewed out so much ejecta they collapsed inward forming great calderas (think Crater Lake in Oregon). The best known of these San Juan calderas is probably the La Garita Caldera associated with a “Supervolcano” erupting about 28 Ma (location: east of Creede). The caldera is huge, something like 22 by 47 miles. The major ejecta from the La Garita explosion is termed the Fish Creek Tuff, a dacite by composition (high silica content). Geologists believe the Fish Creek Tuff occupies an area of ~1200 cubic miles. In contrast the eruption of Mt. Saint Helens in 1980 produced ~0.25 cubic miles of ejecta. (Steven and others, 1976),

Around 25-26 Ma another volcano in the Creede area (current geography) blew its stack and then subsided forming a caldera. This action allowed mineral-rich hydrothermal solutions to rise toward the surface, cooling, and then depositing the rich metallic ores that later produced silver, lead, zinc, and other metals. Along with these ores the hot solutions cooled into quartz, including the lavender to purple, band of quartz termed the Amethyst Vein, and the sowbelly agate.

MinDat (November 2024) lists 95 different minerals from the Creede Mining District obtained from about 100 mines and prospects. However, most of the wealth came from the Holy Moses Mine (discovery mine), Empress Mine, the Amethyst Vein mines: Amethyst Mine, Bachelor Mine, Commodore Mine with the OH Vein, P Vein, Commodore #5 Mine, and the Happy Thought Mine, the Last Chance Mine, Nelson Tunnel, and the Park Regent Mine. Although production figures are a little fuzzy, the Creede District produced about 9,000 tons of lead, 2000+ tons of silver, 4,000 tons of zinc and lessor amounts of other minerals. Today the District is still in the mining business; however, the source of the “ore” is U. S. currency pulled from the pockets of thousands of visitors.  

I picked up this specimen due to numerous, small, gemmy, sparkling, terminated quartz crystals.  These sparks host several darker, almost appearing black, crystals of sphalerite (zinc sulfide) along with a couple of translucent crystals of greenish sphalerite.Width FOV ~6 mm. Collecting was in the "5th level, Commodore Mine."

This specimen appears to be group of goofy looking quartz crystals. Actually the quartz is amethyst with a manganese coating collected from the Last Chance Mine. Width FOV ~6.2 cm.

 Nice, semi-translucent, honey colored crystals of sphalerite with dull gray cubes of galena (lead sulfide)m collected from the Commodore Mine. Width FOV ~4.5 cm.

Interestingly, the mineral creedite [Ca₃Al₂(SO₄)(OH)₂F₈ · 2H₂O] did not come from the Creed Mining District but from the Colorado Fluorspar Company Mine at Wagon Wheel Gap about 10 miles southeast of Creede. The mine was active from 1911 to 1950 and produced fluorite for use as a flux in the open-hearth furnaces at the Colorado Fuel & Iron Company's steel mill in Pueblo, Colorado.

Wire silver covered wit small nodules of acanthite (silver sulfide) and chalcopyrite (copper-iron sulfide).  Collected from the Last Chance Mine. Width FOV ~6-7 mm.

Beautiful, partially tarnished wire silver with a "peeling" top. Length of specimen ~1.1 cm. The Creede Mining District produces some of the best wire silver in the world.

One is never wholly conscious of the greed hidden in one's heart until one hears the sweet sound of silver. . R. Zafon.

BLACK DIAMONDS FROM MICHIGAMME

 It is tough to be a diamond in a rhinestone world! Dolly Parton

 I suspect that most rockhounds have a garnet or hundred in their collection. These silicate minerals have been used as gemstones for millennia, as well as having numerous uses in industry. Collectors love garnets since they are usually easy to identify by their red to reddish brown color (or green or black or pink or violet), by their hardness of ~6.5 to 7.5 Mohs, their crystal habit that is often 12 sided rounded dodecahedrons, and their occurrence in high temperature metamorphic rock like schists, igneous rocks such as granite, and detrital sediments such as sands. The more serious, or even semiserious, collectors define the general garnet formula as X₃Y₂(SiO₄)_3.  This formula is then used to differentiate the 1) Pyralspite Garnets where aluminum fills the Y site: the iron aluminum Almandine, the magnesium aluminum Pyrope, and the manganese aluminum Spessartine and 2) the Ugrandite Garnets where calcium fills the X site: calcium iron Andradite, the calcium aluminum grossular, and the calcium chromium uvarovite. These two major groups are actually solid solution series with intermediate garnet varieties and several mixed cation varieties. Chemists also experiment with several synthetic varieties of garnets where new elements substitute  for silicon in SiO₂ part of the chemical formula.

The fat, quarter-size crystal I want to describe in this post is not one of the common, shiny, dark red, iron-rich, well-defined dodecahedrons of almandine---although it used to be! The specimen was collected from the Michigamme Mine in Marquette Michigan and that locality provided the clue to its description. Greenish black to black chamosite has pseudomorphed the classic dodecahedral crystal of almandine. 

 

A 12 sided dodecahedron of chamosite ps. almandine. Width FOV 1.9 cm.

Chamosite is the iron rich member of the chlorite group of minerals, a hydrous iron aluminum silicate (Fe²⁺)₅Al(Si,Al)₄O₁₀(OH,O)_8.  As a sheet silicate it has a laminar shape similar to the mics. These sheets are usually greenish gray to brown to greenish black in color and are translucent to transparent, and soft (~3 Mohs), and flexible. The luster is usually dull to pearly. Chamosite is in solid solution with clinochlore, its magnesium analog, and both commonly occur in sedimentary iron formations.

 The chlorites, including chamosite, are part of the “clay minerals”, and as such, have very tiny crystals that are often earthy in appearance. In my specimen chamosite has altered, disrupted, and changed the internal lattice and structure of the almandine; however, the external shape, a dodecahedron, has remained. It remains beyond my pay grade to understand exactly “why” or “what caused” the almandine to be replaced by chamosite.

The most famous of the chamosite ps. almandine specimens have been found in the dump piles of the Michigamme Iron Mine, "Marquette Iron Range," in Marquette County, Michigan. Termed “Black Diamonds” by the miners, these very hard specimens were a pain in the derriere for the ore crushers. However, historical accounts noted that local entrepreneurs sold the black diamonds to visitor and tourists, especially those on the trains stopping at the Michigamme Railroad Depot. A note on my specimen stated it was collected ca. 1900.

 Location of the Marquette Iron Range. Public Domain map courtesy of W. F. Cannon, USGS.

The Michigamme Mine, from ~1872 to 1905, produced perhaps, I don’t have good figures, a million tons of iron ore from the Proterozoic Negaunee Iron Formation and the overlying Michigamme Formation. The cherty ore pay rocks were hematite-rich with secondary magnetite and grunerite. I also saw a note that recent Michigan road construction crews have covered the dump piles of the mine with a new road. The reporters were lamenting the loss of again collecting these magnificent black diamonds.

It is more fitting for a man to laugh than to lament over it.

                        Seneca the Younger

 

Almandine garnet crystals on gray-green schist. Public Domain photograph courtesy of Didier Descouens.           

 

CHASIN' THE BLUES WITH JAKE, ELWOOD, KEVIN, BILL, AND BOB

 THIS POST WAS ORIGINALLY PUBLISHED 3-4 YEARS AGO AND HAS BEEN IN DRAFT FORM FOR AN UNKNOWN TIME. IN SCROLLING THROUGH MY POSTS I DISCOVERED IT AND THOUGHT IT NEEDED TO SEE THE LIGHT OF DAY.

Sprays of blue brochanite on quartz terminations (photomicrograph). Width FOV ~1 cm. Photo: Mike Nelson

 

And the idea of just wandering off to a cafe with a notebook and writing and seeing where that takes me for a while is just bliss. J. K. Rowling

Movie Poster, Public Domain, photographer unknown.

In this time of the Covid-19 pandemic and self-isolation my mind wanders, as do the minds of several rockhound friends. That wandering activity is not a “bad thing” as most of us have some degree of ”pandemic depression.  Listen to the advice of newscaster Diane Sawyer,  I've always found a cure for the blues is wandering into something unknown, and resting there, before coming back to whatever weight you were carrying. Between wandering I try to keep busy with other chores (I am tired of raking leaves) and activities.  I read a new book about every three days or so, play with the minerals, devour the newspaper, write letters to the editor (few are published), write/read several hours a day, watch a little TV (mostly older “happy” movies with such phrases as: Jake: That Night Train's a mean wine) , exercise a little, and listen to the oldies music channel : Elwood: What sort of music do you usually have here?  Claire: Oh we got both kinds, We got country, AND western. As you can probably surmise, I have a weird sense of humor and enjoy watching the Blues Brothers: I have four fried chickens and a coke. OK you need the see the two movies to understand the humor of Jake and Elwood!

 

Kyanite, a metamorphic aluminum silicate from Brazil. Photo: Kevin Witte.

Blue halite from the Delaware Basin, New Mexico.  Cube ~2.5 cm. X 2,5 cm. Photo: Mike Nelson.

 

Photomicrograph banded chalcedony left grading into blue chalcedony or silica infused chrysocolla surrounding black tenorite.  Notice green ?chalcedony encased in the blue.  Width of photo ~1.2 cm. Photo: Mike Nelson.

 

My days are not strenuous but are not too exciting either; however, we have food and shelter and family wellness and for this I am happy.  And, as you might suppose I am “retired” with Social Security and do not hold an actual working position and that certainly skews my activities and thinking.  One of the good things about my life is that I am learning much, not only about minerals, but about the world in general, how a virus operates, a new word every day, how bars form a significant part of our social wellbeing, about economics as the price of groceries heads upwards while gasoline trends down, and how scientists are taking a bum rap with this pandemic.  Personally, I am waiting for scientists to conquer the Covid-19 pandemic.

 

Blue-green microcline var. amazonite collected Lake George area Colorado (top), Galway, Ireland (bottom). Photo: Bob Landgraft, bottom; Kevin Witte, top.

 

Lapis Lazuli, metamorphic rock composed of sulfur-rich hauyne (in the Sodalite Group) with lesser amounts of calcite and pyrite.  Photo: Kevin Witte.

 

 

Lazulite a magnesium, iron, aluminum phosphate from Rapid Creek, Yukon, Canada. Width of crystal ~3 mm. Often confused with Lapis. Photo: Mike Nelson

But as I said, my mind tends to wander and this week, for some strange reason, my thoughts moseyed over to the color blue and all sorts of items popped into my mind, like: what is your favorite color?  For me it is blue.  As John Lennon once sang, “The sun is up, the sky is blue” or Judy Garland’s “Somewhere over the rainbow. Skies are blue.” Thinking about blue: 1) there are more songs with blue is the lyrics than any other color; 2) blue is the only color to have a genre of music named after it, The Blues; 3) if one of our 50 states primarily votes for the Democrat presidential candidate, it is a “blue state” 4) and so it goes. As for music:

Blue

Oh, so lonesome for you

Why can’t you be blue over me

Blue

Bill Mack but a big hit by LeAnn Rimes

 

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

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

But don't you step on my blue suede shoes

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

Carl Perkins or Elvis Pressley

 

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

Devil with the blue dress on

Mitch Ryder

 

Blues stay away from me

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

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

Delmore Brothers

 

Got the blues, got the blues

Got the blues, got the St. Louis blues

Louis Prima

 

 

A poster, source unknown, advertising the Delmore Brothers.

 

Namibia

Namibia.

Lake George area, Colorado.

Fluorite, calcium fluoride. Italy. Photos above: Kevin Witte

Fluorite, calcium fluoride. Photo: Bob Landgraft.

What about your favorite Blues genre or blue in the lyrics song?  Do rockhounds have a favorite?  Well, as an ole rock and roller like me (my age is certainly showing) Carl Perkins and Mitch Ryder are tough to beat.  But my all-time favorite is the Delmore Brothers, “Blues stay away from me.”  The music is very haunting (probably because of the tenor four string guitar and the harmonica of Wayne Raney, but it brings back memories of my youth when Saturday night dances were scattered across the rural areas of Kansas. Those dances usually presented a “big band” sound, or “hillbilly” music; rock and roll generally was confined to high school dances.  In the days before cable TV high school or “town team” sporting events, and local dances were the major sources of entertainment in rural parts of our country. Yea, I know very few readers have heard a recording by the Delmore Brothers!  But consider they were stars of the Grand Ole Opry in the 1930s and wrote more than 1000 songs. Perhaps Bob Dylan summed it up best: “The Delmore Brothers, God I really loved them! I think they’ve influenced every harmony I’ve tried to sing.”  So, there you know some of my strange secrets! Take a peek at this youtube recording:  https://www.youtube.com/watch?v=YUk9UDoVyKk

 

Aquamarine, Pakistan. Photo: Kevin Witte.

Aquamarine, Namibia.  Photo: Kevin Witte

Maybe you have a favorite "blue" movie?  Who could forget The Blues Brothers--It's 106 miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark and we're wearing sunglasses. Hit it.  Perhaps Blue Velvet, The Blue Lagoon, Blue Hawaii, or the IMAX film the Blue Planet? But again, I am showing my age.

 

Plumbogummite with pyromorphite, China.  Photo: Kevin Witte.

Barite, Hartsel, Colorado.  Photo: Kevin Witte.

So, what about your favorite blue mineral?  I presume a large segment of the rockhound population would immediately state azurite, the copper carbonate. Others might spout turquoise or zoisite (tanzanite), opal, aquamarine, or numerous others. So, it popped into my head, since we do not have club meetings, ask members of the CSMS to send me photos of their favorite blue minerals.  I was expecting about 50 bored rockhounds to flood the emails! But it appears that most members must be occupied with other important activities and I sincerely thank Kevin Rockhounding the Rockies Witte, the guy who knows about fluorite Bob Landgraft, and Mr. Lapidary Tool Man Bill Kern.  But most of all I thank John Emery, the fantastic Pick & Pack Editor for allowing me to add rather frivolous material to a mostly serious newsletter.  However, the activity perked up my mind and perhaps readers might find a little humor to help put a damper on “pandemic fatigue”.  So, thanks John.

   

Azurite with malachite collected Arizona 1980s.  Photo: Bill Kern.

Quartz, enhanced (radiation?) to form "blue Quartz."  Photo: Bill Kern.

Azurite with Malachite, Cuba, New Mexico.  Photo: Kevin Witte.

I have espoused my views on blue minerals with numerous Blog postings and today have a couple of new, blue, copper arsenates: guanacoite and arhbarite.  You aren’t familiar with them? Neither was I until I found them in a dusty drawer of a small rock and mineral store and started reading.

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

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

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

Closeup of above photomicrograph. Photo: Mike Nelson.

Dark blue arhbarite surrounded by prismatic crystals of guanacoite.  Maximum width of blue mass ~1 mm. Photo: Mike Nelson. Guanacoite is similar to arhbarite in that it is a hydrated copper magnesium arsenate except it has additional water [Cu2Mg3(AsO4)2(OH)4-4H2O]. It has a pale blue to blue color, a white to light blue streak but most important for identification, it usually occurs as prismatic, acicular to bladed, translucent crystals.  Guanacoite is often found as tiny blades lining, or associated with, vugs of arhbarite.  Again, it is a rare mineral only known from the Type Locality, Morocco, and Spain.    The copper zinc carbonate, rosasite (R) and the arsenate mixite (M) from the Tintic district..  FOV ~ 1 cm. Photo: Mike Nelson.