Wednesday, July 22, 2015

A Truly Great Overlooked Maryland Locality


Deserving  serious recognition in Maryland's mineralogical circles for the specimens it once yielded is the defunct Farmers Cooperative Limestone Quarry near the crossroads of New London in Frederick County. The quarry, which produced a dolostone primarily of Wakefield Marble laced with phyllite, ceased operations in 1973. 

The locality found its way to Mindat  thanks to Dr. William Cordua,  now retired  as Professor of Geology at the University of Wisconsin. Over the past 30 years, Dr. Cordua has written more than 50 professional publications, most relating to Wisconsin's geology and/or mineralogy. Among them is  a compendium of Wisconsin species that appeared in  Rocks and Minerals. More thorough is the database of Wisconsin minerals he maintains for the Wisconsin Geological and Natural History Survey. Now a member of Mindat's Management Group, he has enhanced that site's listings for species and/or localities in nine other states, including  Maryland's  Farmers Cooperative Limestone Quarry. Dr. Cordua collected there between 1967 and 1969 while  a geology student living near Washington DC.

He recently decided to  "de-acquisition" some of his collection.  Included were the specimens he collected at Farmers Cooperative,  His wish was for them to “wind up with people who appreciate Maryland minerals.”

The suite appears worthy of consideration as one the most interesting and significant Maryland mineralogical finds in last 50 years. We are not aware of a more aesthetically pleasing Maryland-collected aurichalcite specimen  than the one pictured in our title image. Somewhat visually drowned  out  by virtue of colorless transparency are numerous well defined accompanying hemimorphite crystals. The image at right better captures similar crystals from  another rock in the suite. As with the aurichalcite, we are unaware of a better example of what little Maryland hemimorphite is known to exist.

None of the specimens  in the suite amazed us more than the
transparent green sphalerite crystals on calcite pictured at left. Of obvious gem quality, these crystals form an aggregate extending about  8 centimeters. 


Also significant and pictured at right is green/gray botryoidal crystalline smithsonite inside a 6.5 millimeter vug at a contact point with quartz. It is in a rock richly graced with sparkling blebs of galena. Interestingly, galena is not one of the more abundant species among the primary ore minerals from Farmers Cooperative. Far more common are sphalerite, bornite, and chalcopyrite.


 All  three aforementioned sulfides are ubiquitous in thin ore filled veins occasionally running through the Wakefield Marble for which the quarry was mined. Less common and found separately, were crystals of chalcopyrite, rare in Maryland, especially in association with calcite. The several examples that Dr. Cordua collected  rested on marble topped by drusy calcite, as pictured at left..

Of particular interest is  the specimen shown in the photomicrograph at right. The main crystal is goethite pseudomorph after chalcopyrite with epitaxial prisms of malachite. As most of the malachite from  the quarry was of  was of a darker green hue, Dr. Cordua had originally suspected that these beautiful crystals could be dioptase.

Farmers Cooperative Limestone Quarry is not mentioned in The Natural History Society of Maryland's 1940  Minerals of Maryland, by Ostrander and Price. We suspect the quarry may not  have existed then. However, it is one of but two Frederick County localities mentioned in Maryland Geological Survey's 1981 Minerals of the Washington, DC Area by
Lawrence Bernstein. Among minerals observed in Dr. Cordua's suite  that we have not covered but are are listed in that publication are baryte, hematite, manganese oxides (pyrolusite) as dendrites, and chlorite. Bernstein also noted calcite crystals, but may not have been aware that some of the smaller ones werer as beautiful as the twins  in the image at left, which  Dr. Cordua shot.


Bernstein did not mention hydrozincite, It occurs in white crusts that are less than remarkable to observe until placed under shortwave ultraviolet light as shown  at right.

Minerals of the Washington DC Area  does  mentions gold, cuprite, linarite, and rosasite, all on the basis of "oral communication." The late Herb Corbett provided the oral communication regarding rosasite, which he described as "crusts of tiny green crystals."  However, an x-ray analysis that Dr. Cordua submitted.suggests that this material was aurichalcite, which the book did not mention.

Another publication with particularly interesting information regarding the geology of Farmers Cooperative is  Heyl and Pearre's 72 page Copper, Zinc, Lead, Iron, Cobalt, and Barite Deposits in the Piedmont Upland of Maryland, published in 1965 by the  Maryland Geological Survey. Minerals it names from Farmers Cooperative include are limited to  sphalerite, galena, chalcopyrite "and their oxidation products."  These "sulfides, Heyl and Pearre noted, "occur as replacements of the (Wakefield) marble at the contact of the adjacent Ijamsville Phyllite, and in thin replacement veins, bunches and stringers within the marble band."  The veins, they added, are similar to those at the New London (copper) Mine.

It is intriguing how many species species included in Dr. Cordua's suite have been reported  at three nearby long defunct and grown or built over localities: the aforementioned New London Copper Mine; the Unionville Zinc Mine; and the the Mountain View Lead Mine.. All of these localities, along with Farmers Cooperative Limestone Quarry, are  located within a few miles of each other. The ore and collectible  minerals in Dr. Cordua's  suite comprise a significant partial composite of such species,

In a recent email, Dr. Cordua contributed some updated thoughts:.
The similarity in mineralogy at Mountain View and so forth - distinctive stuff like the green sphalerite - I think prove a commonality in origin to the deposits.  Not sure if the formation names haven't changed as a consequence of subsequent remapping. Certainly their interpretation has. I recall plate tectonics just coming in when I was an undergraduate. The Piedmont is certainly a mess of interlocking terranes, likely hacked up now by major faults but, hey, that made for the diverse mineralogy of the state.
None of the literature mentioned thus far provides as much detail as Dr. Cordua's  field notes taken when he collected these specimens.  In addition to species thus far described, they cite manganoan calcite, chalcocite, tenorite (var.) melaconite) covellite, siderite, and celestine.  The notes suggest varying levels of uncertainty regarding  a presence of native sulfur as well as secondary lead minerals  anglesite, cerussite, all known to have been found in microscopic quantities at the nearby Mountain View Lead Mine.


Today, what is left of the Farmers Cooperative Limestone Quarry is filled with water and posted with a no trespassing sign. The remains of an old wooden building still stand, and evidence of trenches and a small foundation are discernible. We saw no evidence of any remaining dumps, especially through the thick midsummer vegetation,




Monday, July 6, 2015

Getting Started in Mineralogy by Gemma Burns


Publisher's note:
Mineral Bliss always been receptive to posts written by guest writers who have something to say that's pertinent.  Gemma Burns, a freelance writer, submitted the first such article that we have received and chosen to publish.  We were impressed as to how she managed to compact the essentials to getting started in our hobby into an article of appropriate for a Mineral Bliss post. 

Mineralogy is a fascinating and rewarding area of interest. Not only is it very good for you in general [1] to have a hobby, but the study of mineralogy can vastly improve your general knowledge and view of the world [2]. However, if you’re just getting started up, it’s easy to make pitfalls, to head in the wrong direction, and to make ill-judged decisions through want of better knowledge. Here, therefore, is a short guide to getting started in mineralogy. There is of course no single surefire route to this, and lots of people get into this in lots of different ways, but these tips might help if you’re a bit uncertain!

A lot of mineralogy can be (and is) learned ‘on the job’ – plenty of people got into mineralogy by finding an interesting rock and experimenting with it. However, if you’re really serious about this science, you’d do well to familiarize yourself with the theoretical basics. There are a wealth of books, magazines, journals [3] and websites out there which can help you to increase your store of rock-based knowledge (including our own website!). If you’re just getting started, it would probably be wise to grab yourself a nuts-and-bolts handbook [4] rather than leaping in at the deep end with the more involved academic stuff.

Once you’ve familiarized yourself with some basic mineralogical theory, it’s time to get down to the real business of learning about rocks on a practical level. A great way of doing this is to get a starter kit which contains samples of rocks all the way up the Mohs Scale of Hardness (well, perhaps not quite all the way up – you’d be hard-pressed to find a kit-maker who’ll put a diamond in a practice kit!). Play around with the samples, learning about what they can and cannot tolerate. Not only will this allow you to get close to the object of your hobby – the rocks themselves – it will also aid your understanding of them on a practical level, and give you some valuable experience which will help you to know how to handle various minerals in the field.

Mineralogy isn’t dangerous if done correctly, but it isn’t always the safest of hobbies either. This is part of what makes it so much fun! Your life as a mineralogist may see you heading for some precipitous rockfaces, or putting yourself in the path of falling rocks. If you’re careful and you know what you’re doing, then you’re unlikely to get into any trouble. But it’s worth brushing up on rock safety procedures and ensuring that you and your kit are ready for all eventualities [5] just in case. Get yourself some steel toe-capped boots, some goggles to protect your eyes when chipping out rocks, a helmet, some tough gloves, a first aid kit, and some hi-viz in order to let workers see you if you’re collecting in a quarry. If you’re really serious about safety, you might also want to grab a Geiger counter in order to monitor the minerals you’re working on. Some rocks can emit surprisingly high levels of radiation [6]!

Apart from safety concerns, you’d also be advised to prepare well for any collecting expedition. Get a good geologists hammer, a chisel, a magnifier, and a bag to put your kit and specimens in. Make sure that you’ve got everything you need before setting out – there’s nothing more irritating than finding a really promising specimen, and being unable to get it out for want of a chisel. It’s also really important to get the permission of any relevant landowner whose land you may wish to work on. Not only will they be able to tell you if you’re likely to be disrupting anything of import with your activities, mineralogists who trespass [7] bring the whole field into disrepute. Finally, you’re advised to obtain things like polish and microscopes to aid you in cleaning up and examining your specimens. Other than that, there’s little else you can do apart from get down to the rockface and learn!

[1] Cynthia Ramnarace, “Why You Need To Have A Hobby”, Business Insider, Mar 2014
[2] R Detrosier, "The benefits of general knowledge; more especially, the sciences of mineralogy, geology, botany, and entomology, being an address delivered at the opening of the Banksian Society, Manchester. On Monday, January 5th, 1829", Hathi Trust
[3] Mineralogical Society Of America, "Select Publications"
[4] Sarah Garlick, “National Geographic Pocket Guide to Rocks and Minerals of North America”, National Geographic
[5] Compare "Looking after your collections"
[6] Thomas Harding, “Museum’s rock collection was highly radioactive”, The Telegraph, Feb 2001

[7] Cornell University Law School, “Trespass”

Sunday, May 31, 2015

The Early History of the Baltimore Mineral Society

Your truly wrote  the article that follows for the October, 2014 edition of the Baltimore Mineral Society's monthly newlsetter, The Conglomerate,  Recently, the Eastern Federation of Mineral and Lapidary Societies awarded it "Trophy" recognition in the "Written Features" category for articles that appeared during 2014 in the monthly newsletters.

                    The Early History of the Baltimore Mineral Society
                                                 by Jake Slagle

Depending upon whom you ask, Baltimore Mineral Society can trace its beginnings to 1950 or 1951.  According to charter member Harold Levey, that is when Paul Desautels, then a professor of chemistry at Maryland State Teachers College (now Towson State University), appeared at the Natural History Society of Maryland to see its mineral collection. At the time, NHSM occupied two buildings in Bolton Hill. One was at 2101 Bolton Street. The other, next door at 2103 Bolton Street, housed its mineral collection.   Although at least one cabinet of minerals adorned a main front room, the building’s kitchen was home to NHSM’s more serious collection, which was well organized in drawers that opened and closed. Additional minerals were packed away in the basement.

Charles Ostrander, after more than a decade of being in charge of NHSM’s minerals, had recently
moved to Harford County.  Mr. Levey (pictured at right), then in his late 20’s, was serving as de facto curator. Mr. Levey recalls that during his visit, Mr. Desautels expressed an interest in arranging for gatherings of people who were interested in minerals where they could talk about them.

Mr. Levey, along with his colleagues at NHSM, the late Ed Geisler, John Glaser, the late Charlie Smith, and Jack Kepper were receptive to the idea. Their initial vision was to form such a group as a separate organization that would be affiliated with NHSM, a proposition that NHSM quickly rejected.  

Mr.Desautels subsequently pitched his idea to the Maryland Academy of Sciences, which then occupied quarters on the third floor of the Enoch Pratt Library.  Soon thereafter, he reappeared at NHSM and stated, “We’re going to be partners.” While no such partnership ever took place, Mr. Desautels was now in contact with enough mineral aficionados in the Baltimore area to assemble the kind of group he envisioned without the support of an outside organization.

The earliest meetings took place at Mr. Desautels’ Towson apartment.  John S. White(pictured at left), who was in high school at the time, recalls being one of the founding officers (Treasurer) along with Mr. Desautels, who was President,   and Mr. Levey, who later became President.  Whether or not the group was yet calling itself the Baltimore Minerals Society is unclear.  Whatever its name, Mr. Levey remembers that in short order, Mr. Desautels was producing  its newsletter with a mimeograph machine at the Teacher’s College.

Mr. Levey, Mr. White, and Mr. Kepper all remember that their meetings were monthly.  The group grew and soon made arrangements to hold its meetings in a classroom and/or in the College’s chemistry lab. Both Mr. Levey and Mr. White recall these early meetings as having been much like classes where Mr. Desautels was the instructor.  Learning about minerals and related fields was not simply encouraged, but required, and assignments were part of the agenda.

Via email, Dr. Jack Kepper, who now lives in Arizona, shared further early recollections pertinent to the Society’s evolution.
Paul Desautels taught us about crystallography, chemistry and was passionate about the preparation of micromounts.  Virtually all of the material initially was from his duplicates, but soon we began collecting on field trips. I recall visiting Phoenixville, Frostburg, and the trap quarries in Virginia.  We even went over as a group to Washington DC to the Washington Mineralogical Society.  I don't think we called ourselves the Baltimore Mineral Society – perhaps our group was just a precursor of the society.
On more than one occasion during those early years, Mr. Desautels arranged for well-known micromounters Neal Yedlin and Lou Perloff to visit in order to provide the group with first-rate access to the micromounting niche of mineral collecting.  After a day of working with micromounts, the entire group retired to the Penn Hotel, then a popular Towson restaurant, for a dinner where the emphasis was on fellowship.

After several such annual gatherings, what had by now become the Baltimore Mineral Society formally held its first annual international micromount symposium in 1956 at the College. Afterwards, the group continued to retire to the Penn Hotel, as the smaller group had done in the past.
The following year, 1957, Mr. Desautels left Maryland State Teachers College to become Curator of Minerals and Gems at the Smithsonian.  Future symposia moved to Stemmers Run Jr. High School in Eastern Baltimore County, where BMS member John Jedlicka was Principal. 

Mr. Desautels remained in his Curator-in-Charge position at the Smithsonian for 25 years. In 1963, he hired Mr. White, then a field geologist working for ASARCO in Tucson, to become a museum technician specializing in mineral sciences. While working at the Smithsonian, Mr. White founded  Mineralogical Record in 1970, and after a series of promotions to various curatorial positions, succeeded Mr. Desautels as Curator-in Charge of the Smithsonian’s Division of Mineralogy in 1984. 

Monday, April 13, 2015

In Middleburg, PA: The Other National Limestone Quarry

Less than ten miles away from the above pictured National Limestone Quarry in Middleburg, Pennsylvania,  is another National Limestone Quarry, which became well known about ten years ago after one of its more remote corners proved to be a source for  world-class wavellite specimens. Owned by the same family, the  Middleburg, PA,, National Limestone Quarry is by all appearances a similar kind of quarry, but it is low on the radar of mineral collectors. In fact, as best as we can determine, even  Mindat is unaware of its existence.

Through prior arrangements with the owner, members of the Baltimore Mineral Society and the Chesapeake Gem and Mineral Society received permission to collect at this "dark limestone" quarry in Middleburg on Saturday, April 11, 2015. We knew it had yielded  fluorite and that "cave flowers" had been found on the berms where  collecting was permitted,


We determined the fluorite to be easy to find in cubes  up to slightly more than an inch.It occurs in veins of dolomite within large boulders of dark limestone. To separate the fluorite cubes from the dolomite encasing them is problematic; likewise to separate the dolomite veins from the limestone through which they intrude. Many of the veins are no more than an inch wide. The preferred method for collecting the fluorite is  to  whack the large boulders with such veins using a large sledge hammer and trim away as much limestone as possible from the resulting particles

A higtlight of the day was an encounter with aragonite rubble  that  clearly originated in a cave that had collapsed on a surrounding wall. Unlike the clear to pale orangish brown aragonite stones present on many of the berms, some of this aragonite demonstrated  a presence of  stalactites, stalagmites, and "cave flowers,"  The seven inch stalactite at right proved to be one of the day's premier finds along with nodular stalagmic sections and some crumbly aragonite with vugs containing impressive microscopic orangish brown aragonite needles. Since nearly all caves or caverns in the region where such material exists are public places that prohibit collecting, this quarry provided a rare such opportunity, although  the picking were slim.



Other finds included magnificent dendrites, pictured at left. Also present, were colorless calcite crystals to about five millimeters  as seen at right  within vugs occurring in a very few limestone boulders. The only other material  of notable  interest to be uncovered were  mud crack rocks.

Even with permission to also collect at the nearby National Limestone Quarry in Mt. Pleasant Mills, the Middleburg locality sufficed to occupy our group for six hours. With  two hours of collecting time remaining, we headed to to the Mt. Pleasant Mills Quarry to a spot that yielded fine barrel-shaped calcite crystals.

Tuesday, March 24, 2015

Great Maryland Exhibits; Great Show

The Gem,Lapidary, and Mineral Society of Montgomery County's recent 51st annual show at the 4H building of the Montgomery County Fairgrounds in Gaithersburg raised what otherwise could be a tough question. Where else, and for that matter when, can one actually see first hand a wide range of different mineral species that were collected in Maryland?

The images above show a variety of Maryland species featured in an exhibit entitled Mines, Mineralogists, and Maryland. Each specimen is historically significant as determined by such criteria as locality, the person who collected it, and/or past ownership. Chris Luzier, the GLMSMC's president and enthusiastic curator of the display, has surrounded the specimens with images and memorabilia related to Maryland's mining history as well as to numerous renowned late mineralogists who collected, identified, and studied Maryland specimens.  The collection's previous owner was the prominent Maryland collector Fred Parker, who availed much of his Maryland collection  to GLMSMC before moving last year to New Mexico. Fred acquired the historic specimens from the well-known Collectors Edge mineral dealership, which in turn had acquired them when the Philadelphia Academy liquidated its hidden and neglected world-class mineral collection in 2007. Most of the specimens are from localities that no longer exist. It is unquestionably the ultimate historical display of Maryland Minerals

Pictured above is part of  an additional display of other Maryland collected minerals formerly part of the  Fred Parker Maryland collection. Therein are numerous species beyond those represented in the historic display. Many are from localities not included in the Mines, Mineralogists, and Maryland exhibit

At last year's show, a specimen of Harford County radiated actinolite in steatite prompted our March 24, 2014 post entitled "Historic Maryland Epiphany." This year a specimen appearing similar to an unidentified Hunting Hill serpentine rock in this writer's collection inspired a second, albeit less convincing, epiphany.  It interested me to note that Mindat refers to metaxite as a "synonym for chrisotile," A closer look could be in order. 
Pictured at left is another particularly eye-catching exhibit featuring specimens from the Fairfax Quarry in Centreville, Virginia. They are from the collection of GLMSMC member Jonathan Ertman. Referred to in our November 7, 2009 post as "Maryland's Mr. Hunting Hill Garnet," Jon has focused much of his attention in recent years on acquiring the no longer to be collected classic apophyllite/prehnite specimens for which Centreville is famous. It could be a reasonable conjecture that serious collectors from the Maryland/DC/Virginia area  crave this mineral specimen genre more than any other, possibly even those gemmy Hunting Hill grossulars,

Beyond the aforementioned and about 40 more exhibits on the first floor were numerous workshops, related to lapidary work as well a features to attract the interest of youngsters.  Dealers completely filled the second floor. The GLMSMC sets up the building this way each year, and it works great.

Most of the dealers are from or have strong ties in the region. The range of their offerings is sufficient to interest just about every kind of collector.  Their busiest time is  during the first several hours the first day of the show when aficionados eager for a grab at first pickings all but mob them. Notwithstanding, the pace remains busy, and the wide gamut of dealer offerings continues throughout the two days of this wonderful show. It's not to be missed.

Sunday, February 15, 2015

Contributing to Mindat: A Pleasure and an Honor


It should be safe to say that the gentleman pictured above has done more to enhance the science and hobby of mineralogy than anyone else in history. If you have enough interest in minerals to be reading this, you know that he is Jolyon Ralph, who 14 years ago founded Mindat.org,  the world's largest and most complete public information database about minerals. The site makes it a no-brainer to access and cross-reference whatever you need to know about a  mineral species, from  pertinent facts to localities to hundreds of thousands of images.

 The majority of collectors, dealers, academics, and others with an interest in minerals could not do what they do as well---if at all---without Mindat.org. Most important, access is free to everyone and will continue to be so.

With volunteer input from some of the best mineralogical minds on the planet, Jolyon  created Mindat.org in his spare time as a hobby. Only in the last year did he quit his day job in London, England in order to fulfil the the demands on his time to run it.

As Mindat.org is based in Great Britain,  Jolyon is moving  forward to establish a nonprofit as a US-based 501(c)(3) organization that will make it feasible to secure funds to  continue growing while keeping its database and website  available at no cost.  Until recently, this money came from Jolyon's pocket. To see how Mindat.org will spend the $250,000  it is seeking, follow this link.

One should consider it an honor to contribute to Mindat.org. To encourage early contributions, sponsorships are available at $50 a page for the vast majority of the approximately 4600 mineral species known to exist. This writer, as a Marylander, is flattered to have his name pop up whenever anyone accesses the page for chromite  and williamsite. And for a donation of $1,000 or more you can become named as a Fellow of Mindat.org on the front page of the site.







Tuesday, November 25, 2014

An Historic and Obscure Zeolite Occurrence at Monkton, Maryland

Pictured above is an historic specimen displaying numerous microscopic chabazite and heulandite crystals at a contact point on a slab of Baltimore gneiss. Pursuant to the labels, it was collected at Little Falls near Monkton in Baltimore County, Maryland. The orignial label is from from the collection--- or dealership--- of Germany's late Dr. August Krantz (1809-1872) and identifies the featured species to be haydenite and beaumontite, as chabazite and heulandite  respectively were referred to at the time. The specimen was later in the collection of Jeff Weissman, a renowned mineral photographer and rare species expert.
I acqurired it from John Betts with labels that go well beyond the call of duty to document the provenance. Though  not noted on the label, John also expressed a belief that the specimen could very likely have been collected from excavations near Monkton for the Northern Central Railroad line during the 1830's.


After ceasing operations in 1972, the former NCR rail line was converted into a popular rail/trail in 1984. It  is known today as the Torrey C. Brown Trail and crosses Little Falls about 1.7 miles north of Monkton just before it flows into the Gunpowder River  The Baltimore gneiss in which the chabazite and heulandite are present is indigenous to this specific area. It is more prevalent, however, farther south in Baltimore City and was quarried there extensively in the 19th century for building stone. Interestingly, the chabazite and heulandite appear on the gneiss in a manner that is visually similar to known historic specimens collected  at the Jones Falls Quarries. Some of these can be viewed on  Mindat.

Such historic specimens from Maryland localities of which no remnants still exist can be fascinating to those with interest in the regional mineralogy. For certain, we have much to learn from them. On the other hand, the localities attributed to them can become misleading when the names by which their localies were once known change and become forgotten or confused.

With this specimen, however, the documentation is sufficient to suggest that it is everything the labels claim. To the best of our knowledge, it could well be the only currently known occurrence of these two zeolite species to be reported from the Baltimore Gneiss in Baltimore County (as opposed to the City of Baltimore) or for that matter the only chabazite and/or heulandite specimens to be reported from anywhere in Baltimore County.