Monday, April 13, 2015
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
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.
Sunday, February 15, 2015
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
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.
Wednesday, October 22, 2014
This post is about a world class mineral collection and its collector, Peter Via, of Roanoke, Virginia.. While passing through this increasingly vital city three years ago, I visited Mr. Via and viewed his assemblage of minerals, It was overwhelming to the point that the amount of time we had scheduled for me to view it was far from sufficient.
The minerals fill intricately crafted modern wooden cabinets in which custom halogen lighting showcases each one. Magnificent as they were to view, photographing them proved challenging enough that only about twenty of approximately one hundred hurriedly shot images proved pleasing. Despite the superb lighting, good images of such specimens are best captured by removing each piece individually to a studio setting in order to avoid reflections from nearby minerals as well as interference from the intersection of well-finished wood and the thick glass upon which the specimens rest. An alternative technique of maneuvering the camera within an open cabinet might produce a few more decent images, but could easily lead to the disaster of knocking over and damaging treasures of untold value.
Such risk is why, when asked to loan specimens for display at shows, Mr. Via's response is a "blanket no," All the minerals from his collection that are available for the public to to view are those he has generously gifted to museums, primarily James Madison University Mineral Museum in Harrisonburg, Virginia.
Peter Via himself is no more likely to be present at shows than the minerals in his collection. "If I went,"he once told The Robb Report, "I'd come back with my entire net worth in the back of an 18-wheeler"The reality is that when Mr.Via acquires a mineral, the provider of it hand delivers the specimen to his home. He is willing to pay top dollar, but notes: "It's like the stock market. You've got to know what you're doing." Unlike many high-end collectors, however, he does not view the minerals in his collection as investments.
When viewing these specimens, one is likely to wonder about the possibility that they could be the most desirable of their genre or "best of species" known to exist. When asked about this, he responds: " I can't say I know. No one ever knows what's out there sitting in someones closet."
Like all collectors, Mr. Via will occasionally sell a specimen or two. "Sometimes when they come here to sell me minerals," he explains, "I'll want to get something out for the sake of space. I'm happy to let it go for any reasonable amount I can get, but I'm not about to lose money." He has no intention of ever selling the collection itself, Ultimately, he intends to bequeath it to the Tellus Science Museum in Cartersville, Georgia.
Thursday, September 25, 2014
The shows that were happening in Denver over the weekend of September 12-14 at that city's Merchandise Mart, Ramada Plaza Hotel, and the Denver Coliseum were great. The only regret I had was that my ten Colorado-booked days spanned the week following these shows rather than the previous week. As a result, I missed the Colorado School of Mines Geology Museum's open house in nearby Golden on September 10.
Headquartered in its present modern building at 1310 Maple Street since 2003, and featuring two floors of superb exhibits relating to Colorado's legendary mineral heritage, the museum was founded in 1874. Its star has been rising ever since---more than ever in recent years.
Having never had the opportunity for a visit, I made a point of detouring to Golden after the Denver shows were over. While the Museum's exhibits run the gamut of earth sciences, cabinets full of minerals predominate, especially on the main (top) floor. They are arranged mostly according to locality, with separate cabinets devoted to minerals from Arizona, Mexico, Europe, China, South America, and various other locations. Minerals collected in Colorado fill the greatest amount of space, with separate exhibits devoted to counties and districts of Colorado's mineral belt. Included are the Aspen District, San Miguel, Ouray, Boulder County, Gilpin County, the Leadville District, Clear Creek County, the Gilman District, the Creede District, Teller County and Cripple Creek. In addition to separate exhibits of gemstones and pseudomorphs, I was delighted to also find an exhibit proclaiming the pleasures and merits of micromounting.
After an hour or more of browsing and ogling, I recognized through an open office door Dr. Bruce Geller, who has been the museum's Director since 2007. My timing for looking in to introduce myself and say hello could not have been more auspicious. With two collection managers, 16 student aides, 75 volunteers, and three additional buildings to oversee, Dr. Geller is also responsible for the coordination of nearly daily guided public tours, mostly for tourists and students. As luck would have it, the next guided tour was to be for Yours Truly alone.
Pictured above and particularly impressive is a cabinet filled with an extensive, diverse, and downright amazing rhodochrosite suite on loan from Dennis Streetman.
Dr. Geller's enthusiasm continues as we walk around the larger hall, where he points out specimens he believes worthy of being considered "best of species". The pyragryite piece from the Parano mine at Fresnillo in Zacatecas, Mexico, pictured at left, speaks for one such specimen. Another, shown at right, features an enormous columbite crystal in albite from Minas Gerais, Brazil, Viewed live, its grandeur appears all but unbelievable. To the best of Dr. Geller's knowledge, it is "the biggest columbite crystal in the world." Both specimens, as well as numerous others that are clearly world class were donated by Oreck Corporation founder David Oreck and his son Bruce.
As we return upstairs, Dr. Geller is once again available and proceeds to further enhance my awareness of what the Museum is about. He begins by pointing out its most recent coup. It is a mural consisting of six paintings showcasing the history of mining from Paleolithic times through the 1930's. The paintings extend a short distance out from the west wall about two feet below the ceiling. Irwin Hoffman painted them for the 1939 Golden Gate Exposition in San Francisco. Thereafter they graced Colorado School of Mines Berhoud Hall and later the National Mining Hall of Fame before being transferred here when the Geology Museum moved into its present quarters. Damaged by water that seeped in during a severe 2013 rain storm, Dr. Geller employed the services of restorers, framers and other artisans to have the mural up in time for the Museum's September 10 open house.
Later he mentions that the Museum maintains four warehouses. One is the large storage and study area adjoining the first floor where Richard Parsons showed me the micromounts. The other three have separate locations. They include a second warehouse filled with rocks and minerals. A third warehouse is for fossils, The fourth warehouse holds radioactive material and is "so hot," he says, "I've only been in there twice."
As the afternoon winds toward an end, Dr. Geller speaks of a practice that differentiates the Colorado School of Mines Geology Museum from many other museums. It does not allow all the material that goes into its warehouses become lost or forgotten.
Dr. Geller explains:
On Average, we receive roughly one worthy donation per day, which creates a challenge for our Collections Managers, who must discriminate what is essential from what is superfluous. We are fortunate for the donations of earth science materials and rarely turn them down. We have several options for the overflow: our Gift Shop, our campus labs/classrooms, our give away box at the museum entrance, and one or two annual Garage Sales of generally low-end unlabeled material.
Sunday, August 31, 2014
This is a section of the stream where mica schist, quartzite and quartz account for most of what is around. The latter two often bear stains of iron oxide. A few cobbles, when cracked open, show vugs bearing weathered hematite and/or goethite. Less frequently, one might find a rock similar to this one where the quartzite bears a coating of drusy quartz that's become variably smoothed since entering the stream, The drusy quartz may or may not be botryoidal, as it is with this specimen
What everyone who has seen this rock finds to be curious are the concentric circles. A likely conclusion could be that they are fossils, or fossil imprints. Although it's possible, even with with a matrix of quartz or quartzite, such an occurrence would seem highly unlikely at this location in the eastern section of Maryland's Piedmont.
Much if not most of the approximately one square mile of land surrounding where Mr. Shelley found this rock was once the site of various filled in and built over gneiss quarries that yielded a diversity of interesting mineral species. These quarries and their minerals were the subject of numerous classical mineralogical reports. We are not aware of any literature noting the existence of fossils in the area.
Very recently, we showed this rock to my friend John S. White, who having been Curato-in Charge of the Smithsonian's Division of Mineralogy for nearly eight years, could be the source of a credible opinion. After checking it out under the scope, he was as mystified as everyone else who has seen the specimen regarding its circles. His one firm opinion was to rule out the likelihood of a fossil. His reasoning was as follows:
- I didn't see any organic looking surfaces.
- While there are a couple of prominent concentric circles, there are plenty of circles that are quite irregular.
- There does not appear to be any evidence of a sedimentary environment.
What, then, expllains these circles? We're hoping that someone will submit an answer about which he/she feels confident.