Two of my favorite classes in grad school were optical mineralogy and optical petrography. As the names imply, during the first semester we used petrographic microscopes to identify minerals as seen in thin sections. I have noted previously that I was never a stellar student in undergraduate mineralogy class, mostly due to crystallography. I just had, and still do, problems with visualizing and describing, three dimensional objects. Systems, Classes, Space Groups, symmetry, etc. just fogged up my brain. I was about ready to switch to another major, which would have been my fourth, when the crystallography section ended and we moved on to the physical, and understanding, aspects of minerals. Of course, in the spring semester I hit structural geology and stereograms/stereonets and about went bananas. Who thought up these objects of torture? Why was I being punished when all I wanted to do was hunt for fossils? Somehow, I advanced in the curriculum to “fun” courses like geomorphology, sedimentary geology, and the paleo sequence.

I was sort of terrified in moving on to grad school and finding out that the optical sequence was required for graduation. Then something happened—I loved the classes, the identification of minerals in the fall and following that with petrography in the spring semester where we learned how to better understand igneous and metamorphic rocks via examinations of thin sections. My life became much better, and certainly more exciting.

At any rate, our instructor owned several professional books that were available for use and stored in the lab. For some reason one particular go-to reference stood out in my mind: Petrography of the Igneous Rocks by Albert Johannsen, a Professor at the University of Chicago. Although Johannsen was no longer living in the mid-1960s, in those days I was awed by anyone teaching at Chicago, and certainly the Field Museum paleontologists who wandered around western South Dakota. Then there was the WOW factor, a commemorative plaque on campus stating: On December 2, 1942 man achieved here the first self-sustaining chain reaction and thereby initiated the controlled release of nuclear energy. The first self-sustaining nuclear chain reactor, an “atomic pile” officially dubbed CP-1 (Chicago Pile-1), operated under the stands of the former football stadium, Stagg Field. This pile of bricks and timbers was able to control nuclear fission. And so, the race was on and never stopped.

But the most remarkable item, at least in my young mind, was that Johannsen’s tome consisted of several volumes, four or five at least. My just developing mind wondered how could one person write “so much”? As MinDat stated: “He established quantitative definitions of rock analysis and rock classifications as well as redesigning the petrographic microscope. His descriptive multi-volume Petrography of the Igneous Rocks is a classic in petrography. The scholarly opus has lasted through several editions, thousands of students, and even today can be located on web sites of used book sellers. Although numerous later authors have published multiple books on the classification and description of igneous rocks, Johannsen’s works seem to be the father that started it all. Fortunately, today’s authors have much more information supplied by modern electronic gizmos.



Johannsen’s original research appeared in over 40 scientific papers and books but his early contributions were papers dealing with improvements of the petrographic microscope, and how to identify minerals using a pet scope: Determination of Rock-Forming minerals (1908), Manual of Petrographic Methods (1918), and Essentials for the Microscopic Determination of Rock-Forming Minerals and Rocks in Thin Section (1922).



J. Swift & Son, Dick Model Petrographic Microscope, 1891.





J. Swift & Son, Dick ‘New” Model Petrographic Microscope,1910.

Johannsen, in his Manual of Petrographic Methods, described a number of different pet scopes and featured the Newer Dick Model shown above. Goren ( date unknown; see references) stated that the first scope capable of “quantitative scientific work was undoubtedly the petrographic microscope by AB Dick, whose principle he described in 1889 and which was conducted in 1891 in the catalogs of the company Swift & Son (color photo above courtesy of Dr. Yuval Goren). The “Newer Dick Model” was illustrated in the 1910 Swift catalog. I was unable to find out if Johannsen used a Dick Model scope; however, since he was an admirer of German scholarship I would bet on a Leitz!

Johannsen retired in 1937 (b. 1871) and the remaining years of his life were spent in nonscientific pursuits. Evidently, he had a interest in the nickel and dime novels of the late 19th century. Actually, it was more than just “an interest” since he wrote two volumes of the well respected The House of Beadle and Adams and Its Nickel and Dime Novels (1950). In reading this sentence I became completely confused about who/what was Beadle and Adams. OK, the following information comes from Registry.clir.org/projects/2028/.

By 1864, Beadle & Adams had sold more than five million dime novels, making them one of the most successful publishers in the country. The secret to this success was undercutting rival publishers by selling novels for a dime, which was significantly lower than the going rate of a dollar. This was achieved by using inexpensive paper, exploiting cheaper postage rates for periodicals, and reprinting previously published works. Although their popularity waned towards the end of the century, they were among the most significant and innovative publishers of their time, single-handedly responsible for popularizing the dime novel format and playing an important role in the evolution of American popular fiction. Johannsen’s novel, The House of Beadle and Adams and Its Nickel and Dime Novels (1950), was a landmark work in the study of 19th century popular literature and publishing.

While working on his book, Johannsen amassed one of the largest private collections of dime novels and story papers in the United States, that was purchased by Northern Illinois University in 1967. This collection contains 6,593 publications issued by Beadle and Adams between 1852 and 1897. Johannsen's The House of Beadle and Adams and their Nickel and Dime Novels (1950), is one of the most significant works of dime novel scholarship and bibliography of the 20th century.

In 1932 W. T. Schaller, speaking at the December meeting of the Mineralogical Society of America, described a new manganese pyroxene that he was naming johannsenite “in honor of Professor Albert Johannsen of the University of Chicago”. Because Schaller wanted to study additional specimens that were showing up from several new localities, the official publication date of the mineral name did not happen until 1938 with the publication of W.T. Schaller, Johannsenite, a new manganese pyroxene: American Mineralogist, 23 (9) 575-582. To further confuse the issue, Schaller based his description on material from Tetela de Ocampo, Puebla, Mexico, and nine plus other locales. MinDat lists two localities in Italy and Franklin, New Jersey, as the Co-Type Localities. Lauf (2010) believes the locality at Puebla, Mexico, has the strongest claim for the Type Locality. Interestingly, rockhounds collecting in the western U.S. are partial to getting specimens of johannsenite from the Iron Cap Mine in the well-known Aravaipa Mining District, Graham County, Arizona.

The Iron Cap Mine is a former surface and underground Pb-Zn-Ag-Cu-Au-Fluorspar mine where the major ores were sphalerite (zinc) and galena (lead). Mineralization is found in vein deposits hosted in the Horquilla Formation (Pennsylvanian) and the Pinkard Formation (Cretaceous). Some ore veins occur in faults between formations while others are found wholly in the limestone beds. The mine area also includes numerous intrusive veins of Cretaceous and Tertiary age cutting across Paleozoic rocks (Simons and Munson, 196).

Johannsenite is a somewhat uncommon calcium manganese silicate [CaMnSi2O6], sometimes containing iron, and is the dominant pyroxene from the Iron Cap Mine. The physical properties of johannsenite vary: color ranges from brown to black to gray to green to light blue to yellow to violet and others; it is translucent to transparent; the habit is massive to acicular needles to radiating aggregates to splintery; the luster varies from greasy to vitreous and the hardness is 6 (Mohs), although the acicular needle masses break apart easily. It usually forms in contact metamorphic zones associated with skarns. Johannsenite in my specimens is composed of massive green prismatic crystals or cleavage fragments (angles of 870 and 930 typical of pyroxenes). A second specimen of johannsenite from the Iron Cap has very dark green patches of acicular crystals.



Crystals of elongate “pyroxene-like” crystals of johannsenite. Width FOV ~ 4.5 mm.



Mass of slender, acicular crystals of johannsenite. Width FOV ~7 mm.



Johannsenite, pyroxene-like crystals with white nekoite. Width FOV ~ 5 mm.

Johannsenite is in solid solution with hedenbergite when the iron completely replaces the manganese [CaFeSi2O6] and with diopside as magnesium replaces the manganese [CaMgSi2O6]. In a process that somewhat confuses me, johannsenite alters to pink rhodonite (see Livi and Verblen, 1992, for a detailed report on this process.). The Iron Cap has produced hedenbergite associated with johannsenite but not diopside.





Clear to white to reddish brown bustamite collected from the Langban ore body, Varmland, Sweden. Width FOV both photos ~ 5 mm.

Bustamite [CaMnSi2O6] is the high temperature polymorph of johannsenite and usually forms where manganese -rich ore bodies are subjected to metamorphism/metasomatism, often in skarns. The temperature break is ~830 degrees C. Bustamite is associated with johannsenite at the Franklin Mine in New Jersey but not at the Iron Cap.



Individual crystal of manganbabingtonite from the Iron Camp Mine. Length ~2.5 mm.







Crystals of manganbabingtonite with acicular crystals of johannsenite. Collected at Iron Cap Mine. Length of left largest crystal ~3 mm.

Finally, The Iron Cap Mine is also known for: 1) the magnificent crystals of manganbabingtonite, a rare Ca-Mn-Fe silicate [Ca2Mn2+Fe3+Si5O14(OH)] that is the manganese dominant analogue of babingtonite; and 2) nekoite, a rare, white, hydrated, calcium silicate [Ca3Si6O15 · 7H2O] that was originally confused with the “zeolite look-a-like”, okenite. Nekoite is an anagram of okenite!



Botryoidal masses of white acicular nekoite crystals. Width FOV ~5 mm.




Nekoite clusters with unknown colored crystal. Width FOV ~3 mm.



RFERENCES CITED

Goren, Yuval, www.microscopehistory.com; Retrieved December 2025.

Lauf, R.J., 2009, Collectors Guide to the Pyroxene Group: Schiffer Publishing, The Limited.

Simons, F. S. and E. Munson, 1963, Johannsenite from the Aravaipa mining district, Arizona: American Mineralogist, Vol. 48, No. 9-10.

Schaller, Waldemar T. 1938, Johannsenite, a new manganese pyroxene: American Mineralogist, Vol. 23, No. 9.

OF INTEREST (taken from a Memorial written by F.F. Pettijohn). Johannsen was a Man of Letters and a Polymath.

Johannsen received a B.S. degree in architecture from the University of Illinois in 1894.

He returned to school and received a B.S. in geology from the University of Utah in 1898. He then went to the Johns Hopkins University where he received his Ph.D. in petrography in i903.

Johannsen was pre-eminent in the field of microscopical petrography. He probably was, in a sense, the greatest and last of the American school of petrographers.

He is best known for his translation of Weinschenks' "Fundamental Principles of Petrology”.

His original contributions appeared in some 40 papers in the technical journals. Chief of these is his quantitative classification of the igneous rocks.

He set a standard of excellence that puts most contemporary scholarship to shame. In a sense Johannsen's scholarship was a kind of Iiterary scholarship.

He regarded a good rock description as something of permanent value

Johannsen was a collector at heart. At the time of his retirement, he left a superb collection of nearly 5,000 rock specimens at the University of Chicago. For most of these he had thin sections.

Johannsen's collecting extended to many fields outside of geology including postage stamps, commemorative half dollars, U. S. vice presidential autographs, first editions of Charles Dickens' works including the M EMORIALS 457, famous Phiz illustrations, and dime novels

He was an accomplished artist and when a student in Utah he drew the fashion plates for the Salt Loke City Herald.

He was also skilled in oil painting. He was a photographer of merit and a Leica enthusiast long before 35 mm cameras became popular.

This cultural heritage explains to some degree Johannsen's admiration of the best in German scholarship, his own mastery of German, and his unsurpassed works in the "Handbuch" tradition.

In 1967 many Ph.D. granting institutions believed that one could not be a geology scholar without understanding and reading German. Therefore, I spent a year trying (without high success) to read German and pass the “reading test.” I passed it. Wow. Next came French, and a pass.

I and thankful to Professor Yuval Goren for allowing use of his microscope photo taken from his tome. www.microscopehistory.com This web site is an amazing and brilliant piece of work and readers should take a good look at this comprehensive history of microscopes.

GOLD FROM MARYLAND?-YEP

 

Here in the Wisconsin woods winter seemed to arrive suddenly in early November. We were in a nice fall weather pattern with moderating winds tumbling down the maple leaves while I tried to keep the piles from a heavy covering of the grass. Boats were still on the river targeting freshwater river sturgeons and catfish. The “smarter” residents of my small neighborhood were in short sleeves installing outside Christmas lights and decorations. Then one night I heard the wind whistle in and here came Old Man Winter with freezing temps and in a couple of weeks night temps below zero. Thanksgiving arrived with blustering cold winds and snow while my spouse, daughter and I washed pots and pans for three hours at the community dinner. Then additional white stuff arrived, and the snow blower was cranked up several times. The big post-Thanksgiving events were: 1) the full moon, AKA the Cold Moon, arriving on December 4 floating above the eastern River bluffs as it started its journey across the sky to the western bluffs; and 2) the appearance of the first ice fisherman on the backwaters—a sure sign that winter had “really” arrived. In fact, we seem to be in the middle of several polar vortices keeping the temps “chilly”! Today, the 16^th of December, we are in a warm spell---the first time in several weeks the daytime temp was above freezing. Four days ago, the temp dropped down to at least 10 below with wind chills in the minus 20s. Hard water is here and the ice fishers are scattered on most bays, many snug in their little houses compete with heaters and TVs (to watch the Packers play football).

But the autumnal change to the cold season is a good thing for old rockhounds—I can hibernate in the downstairs office and play with minerals without being concerned about much outside yard work.  And the first of December is a sure sign that the Tucson shows are but two months away. Last year I missed the shows due to “settling in”  at our new abode in Wisconsin. Not so this coming season as Tucson here we come!

I am not a big spender at mineral shows but am usually happy with my buys/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.    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 minerals.  That is one reason I enjoy the professional, but semi-hard core, journals like Mineralogical Record and Rocks and Minerals. I joined mineral clubs inMaryland, Washington D.C., and eastern Canada to get a “non-western U.S. perspective” on geology and minerals and now read several eastern mineral club newsletters that 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. Thoreau.

In rumbling around my basement office/storage I came across one of Willard Wulff’s specimens, gold no less, that I purchased a decade or so ago for about $3 at an estate sale. Willard W. Wulff Sr. was a Charter Member of the Colorado Springs Mineralogical Society who collaborated with Lazard Cahn to start the club in 1936. The specimen is mounted on a pedicle in a smaller Perky Box with handwritten labels in Wulff's very distinctive printing style. He acquired the specimen in 1962. I have a substantial number of Wulff's micromounts, in excess of 100, including several more gold mounts.

The gold was collected from the Maryland Mine, one of a group of gold mines-- the Ford, Anderson, Watson, and Maryland--- clustered in the southern section of Montgomery County, Maryland, near the town of Potomac just northwest of the Beltway near the Great Falls of the Potomac. Today, the Maryland, Ford and Anderson are part of the Chesapeake & Ohio Canal National Historic Park. These mines, along with at least thirty other gold mines and placers found in and around Montgomery County, are situated in the northern tip of a gold-bearing belt that extends in a shallow arc across the Piedmont from northeastern Alabama through northern Georgia, west central South Carolina, central North Carolina, central Virginia, and into south central Maryland. Within this region many gold mines were discovered and operated, beginning in the late eighteenth century, including the included the famous Dahlonega District of Georgia (Nagy and Parker, 2013), site of the first gold rush in the U.S. (1828) that resulted in forced removal of Native Americans (Trail of Tears), and the establishment of the Dahlonega Mint to mint gold coins (D mint mark) from 1838-1861).  

 

 

Reverse of an 1843 gold half eagle struck at the Dahlonega Mint. Public Domain photo courtesy John Reich. Note small D variety mint mark.

 The country rocks in the Maryland Mine area are complex, to say the least, that are part of the Neoproterozoic (~750 Ma) to Cambrian (~550 Ma???)  (they really don’t know its exact age) Mather Gorge Formation (Wissahickon Schist during my classroom days) that formed as the Supercontinent Rodinia broke apart (creating the proto-Atlantic Ocean). Originally the rocks were deposited as clastic sedimentary rocks shed into emerging oceanic trenches but later were subjected to regional volcanism and metamorphism during the Taconic (roughly Ordovician ~450 Ma), Acadian (roughly Devonian ~400 Ma), and Alleghenian (toughly Permian ~290 Ma) Orogenies. Today the country rock seems a mixed-up mess of interlayered mica schist and metamorphosed graywacke cut by dikes, sills, and small irregular plugs of light-colored granite and, locally, of lamprophyre. I have always had a great deal of respect to the mapping geologists working in the Appalachians.

 

The Maryland Mine, and others in the area, exploited quartz veins covering an area of about .25 miles wide by 3 miles long and ranging from a few inches to 14 feet in thickness that are part. They may be part of the Mather Gorge Formation but were probably formed later when late-stage, silica-rich, hydrothermal waters invaded cracks and fissures in the country rock. The gold and sulfide solutions traveled along (Nagy and Parker, 2013).

 

 Gold on quartz matrix from Maryland Mine. Width FOV ~ 7 mm.

 The Maryland Mine has an interesting history. Although extraction started around 1867 and the mine officially closed in 1940 as WW II was looming, it seemed to never live up to its potential as stated by the promotors. In 80+ years the Mine underwent numerous owners and investors, but “unlimited riches” never seemed to evolve and soon a new owner took over with big dreams. From ~1940 to 1951 “locals” prospected, panned, and broke rocks looking for the gold lode. One ounce of gold was shipped in 1951. Interestingly local panners are still able to collect dust, and a few nuggets, in the area’s streams. However, the Mine, and its associated dumps and trenches, are part of a National Historic Park and any sort of collecting is prohibited.

 

REFERENCES CITED

Nagy,J. & F. J. Parker, 2013, The Maryland Mine: Maryland's last underground gold mine: Rocks and Minerals Vol. 88, No. 5

DESAUTELS MICROMOUNT SYMPOSIUM AND DESAUTELSITE

 

I am a member of the Baltimore Mineral Society and have attended most monthly meetings for the last five years. Now Baltimore is a far distance from either Wisconsin (current home) or Colorado (past home) and purchasing airline tickets every month would break my Social Security budget! However, since the “Covid Pandemic” the Society has met via Zoom and even today their meetings are a hybrid with both Zoom and in-person. At most meetings the Zoom attendees from about 7-10 states and a couple of international locations often “outnumber” the in-person event. I feel very much at home via Zoom and the group has very lively and participatory mineral discussions. In addition, I have presented ~4 Power Point programs and contributed several manuscripts to their Newsletter.  Interestingly, many of the members seem like “old friends” although I have not personally met any of them and most likely will never attend an in-person event (due to expenses).

Each year the Society sponsors the Desautels Micromount Symposium and is the home of the Micromounters Hall of Fame. The Hall honors those who have supported and promoted micromounting during their collecting career.  In the early years, the Society honored “modern awardees” and a few “old timer awardees.”  In 1981, the initial year, Paul Desautels was inducted along with “old timers” George Fiss (d. 1925) and George Rakestraw (d. 1904). In examining the Hall of Fame recipients I noted the names of Lazard Cahn, 1982, the Honorary President for Life of CSMS, Arthur Roe, 1993, a founding member of CSMS who studied under Cahn, Jim Hurlbut, 2011, from the Denver area and a force in the Rocky Mountain Federation, Shorty Withers, 1995, the Honorary Curator of Micromounts at the Denver Museum of Science, and Arnold Hampson, 2012, of Cortez who donated his micromount collection to the Colorado School of Mines. Two micromounters are inducted each year with the 2025 inductees being long time collector Ron Gibbs from Arizona and David Roe who has wandered around and collected in Devon, England, UK, for decades.

Paul Desautels (1920-1991), for whom the Symposium is named, held many professional positions in his career but perhaps is best known for his 25 years spent as Curator of Gems and Minerals in the Department of Mineral Sciences in the U.S. National Museum of Natural History, AKA Smithsonian Institution. And perhaps, he was “the most influential curator of the 20^th century”. Desautels was awarded the Carnegie Mineralogical Award for his mineralogical contributions, the Smithsonian Director’s Medal, and the Tucson Gem and Mineral Show created an annual award for “mineral collecting connoisseurship” named the Desautels Trophy. Above from Hall of Fame .

In 1979 Desautels was honored when a new carbonate mineral was collected from the Baltimore Mafic Complex (1.1-1.0 Ga) in a Pennsylvania aggregate quarry (Cedar Hill)  and was named desautelsite [Mg₆Mn₂(OH)₁₆[CO₃]-4H₂O]  (Dunn and others, 1979).  It is a rare, bright orange mineral associated with fractures and cracks in rocks called serpentinite. These exposed metamorphic rocks (layered ultramafic, mafic, and volcanic rocks) are composed of  magnesium silicates formed by hydration and metamorphism of mantle rocks along boundaries of tectonic plates.  Several other secondary magnesium minerals are usually associated with desautelsite, including artinite [Mg₂(CO₃)(OH)₂-3H₂O)], and hydromagnesite [(Mg₅(CO₃)₄(OH)₂-4H₂O] although desautelsite is the last mineral to form in the fractures.

 

Druse of orange desautelsite on matrix. Width FOV ~ 4 mm. 

Desautelsite is a very soft mineral (2 on Mohs) with translucent pseudo- hexagonal crystals forming an orange, druse-like, scaly crust.  Without a powerful microscope the individual crystals are exceedingly difficult to observe.

Desautelsite is an extremely complex mineral, especially to an old plugger like me. It is a member of the Hydrotalcite Supergroup defined by their “natural layered double hydroxides…characterized by layered lattices (metal hydroxide layers alternating with carbonate and/or sulfate anions).”  I have poured over the defining article by Mills and others (2012) and my meager knowledge of crystal chemistry is just not sufficing for an adequate understanding.

MinDat (accessed 30 November) described the Super Group Hydrotalcite as containing, among others, desautelsite [Mg₆Mn₂(OH)₁₆[CO₃]-4H₂O], pyroaurite [Mg₆Fe³⁺₂(OH)₁₆[CO₃]-4H₂O] the iron analogue (whose Xray powder pattern is indistinguishable from desautelsite), and their solid solution group members stichite [Mg₆Cr³⁺₂(OH)₁₆[CO₃] - 4H₂, and hydrotalcite [Mg₆Al₂CO₃(OH)_{16 -}(H₂O)₄]. And then throw in iowaite [Mg₆Fe³⁺₂(OH)₁₆Cl₂ - 4H₂O], described in an October 19 Post, and which may weather to pyroaurite, and readers can understand my confusion (Defeat is not the worst of failures. Not to have tried is the true failure: G.E. Woodberry).

Although the Type Locality of desautelsite is in Lancaster County, Pennsylvania, the mineral is best known from two sites in California, especially the Artinite Pit in San Benito County, an open cut of exposed serpentinized rocks.  Secondary minerals like desautelsite grow on the altered surfaces of the spaces between the breccia blocks.  Other than these localities in Pennsylvania and California there is one locality in Maryland, and three in Japan, where the mineral occurs with other ultramafic rocks.  So, it is a rare mineral.

 

Acicular crystals of artinite, Mg₂(CO₃)(OH)₂-3H₂O, a low temperature alteration product in serpentinized ultrabasic rocks, that is associated with desautelsite.

REFERENCES CITED

Dunn, P.J., Peacor, D.R., Palmer, T.D.,1979, Desautelsite, a new mineral of the pyroaurite group: American Mineralogist, Vol. 64, No. 1-2.

Mills, S. J., Christy, A. G., Génin, J.-M. R., Kameda, T., Colombo, F., 2012, Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides: Mineralogical Magazine, Vol.76, No.5.