Saturday, March 27, 2010

Some Dazzling Maryland Microminerals

This week's post borrows from a brief slide show of Maryland micromounts that I presented this past Friday evening to the Atlantic Micromount conference. Regular followers of Mineral Bliss may have seen some but not all of these specimens before. The cover girl is anglesite from Frederick County's Mountain View Lead mine, photographed at about 30x. The smithsonite image at left, shot with similar magnification ,also hailed from the Mountain View locality. Its colour amazes me. Both specimens were collected about 15 years ago. The self-collected azurite with malachite at right is from my visit there that was described in the Mineral Bliss post of March 21, 2009. It was the only evidence of either of those two secondary copper minerals I encountered.

The much more more spectacular malachite (left) was collected in Carroll County just east of Frederick County at the Lehigh-Portland Cement Quarry near Union Bridge. Most of Maryland's relatively scarce crystallized malachite occurs in acicular crystals. Their different habit and greener than green hue against a backdrop of yellow calcite makes them a personal favorite. The colour of this calcite isn't too different from that of the only wulfenite ever reported from Maryland, which interestingly was collected at this same Lehigh-Portland Cement Quarry locality. All that was ever found was from a single rock uncovered in the 1970's by the late and legendary Maryland collector George Brewer. A flattened pyramid of this wulfenite is pictured at right. Just above it is a cerussite crystal that measures about a millimeter.

The Maryland cerussite crystals below at left are much larger, but not so much so as to preclude being shown in the company of microminerals. They were also collected in Carroll County just a few miles away at the Redland- Genstar Medford Quarry. Though displayed in my collection as a hand specimen, the crystals are better appreciated with the magnification from a macro lens as shown. The rarest and most remarkable mineral ever yielded from the Medford Quarry is the lanthanite pictured at right. As with the wulfenite that was found so close by, all of Maryland's known supply of lanthanite came from one rock. While the nomenclature system for such rare earth species directs that the dominant rare earth element's symbol be shown at the end of the mineral's name, I do not believe such a determination was ever made with this find. A good reason could be that it was too dear and tiny to give any up for testing.

Though Maryland has more than its share of zeolite localities around the state, I'm not aware of any that have produced micromounts more eye-catching than the old-timer chabazite and heulandite pieces that are in Harvard University's micromount collection. Both specimens were from one of the several long closed and covered up 19th century gneiss quarries that operated in Baltimore City's Jones Falls Valley. The chabazite is at left, the heulandite at right.

Maryland's serpentine barrens, all which were once mined for chromium, have also yielded some intriguing micromount material. I feel like apologizing to those who attended my presentation this past Friday night for neglecting to show them the chromian clinochlore (aka rhodochrome, penninite, japanite, miskeyite) pictured at right from Cecil County's State Line Chrome Pits and part of the Harvard collection. The kind of beautiful red quartz crystals at left from the geologically similar Soldiers Delight in Baltimore County are less likely to occur within the vast expanses of serpentine barrens than lining vugs in rocks from its greener wooded areas. Though the land is public and has been set aside for the enjoyment of all, the the removal by anyone of mineral specimens is strictly prohibited with enforcement that's known to be rigid.

Saturday, March 13, 2010

Different Pokrovskite Habits, a Possible New Mineral, Hunting Hill Closed

Despite a 1987 article by John White in Mineralogical Record entitled "Pokrovskite: A Common Mineral" ---pokrovskite is by all accounts relatively obscure. MINDAT currently shows only three images of this magnesium bearing carbonate of the rosasite series and names but seven localities around the world from which it's been reported. Perhaps MINDAT will show more images after I submit two of my own, but we'll have to see. They will differ visually not only from each other, but from all three of the images presently up on MINDAT. One is the micro-photograph at the right end of the above full view, macro, micro progression. The other will be the image at right of pokrovskite bearing a more unusual "satin spar" habit.

During my visit this past December to discuss and photograph Maryland Minerals at the Harvard Mineralogical Museum, its curator Carl Francis more than once mentioned pokrovskite as an example of one of the relatively few rare minerals known to be found in Maryland. He made a point of showing me the Museum's premier specimen with the familiar brown radiating tufts. Later, as I observed and photographed Harvard's Maryland micromounts, the "satin spar" piece turned up. Quite deliberately albeit incorrectly, I referred to the pokrovskite identification as "questionable" in a caption beneath the photograph.

No sooner had I mailed the image (and caption) as part of a "Harvard's Maryland Minerals" CD to Dr. Francis than Fred Parker, who authored "The Minerals of Hunting Hill Quarry, Rockville Maryland," in the September, 2005 Mineralogical Record, replied to a recent Email from me requesting his opinion regarding the pokrovskite identification. "Maybe," Fred wrote."One form of pokrovskite is a 'satin spar' like formation which this resembles." Later in day, once I'd informed Parker that Harvard had obtained the micromount specimen from Fred Shaefermeyer, his response was: "Absolutely. Fred Schaefermeyer was the Prince of Pokrovskite."

Fred Parker and the much older Fred Schaefermeyer were close friends who collected together at Hunting Hill before and through the 1990's. In addition to dubbing Schaefermeyer the "Prince of Pokrovskite,"Parker also spoke of him as the "father of Hunting Hill micromineralogy, a cheerful and intelligent man whose forte was a an eye for picking up minerals that looked different." After his eyesight had declined to the point he could not longer collect, Schaefermeyer dissipated his collection and turned over to Parker several flats of unlabeled Hunting Hill minerals.

Parker sent several pieces about which he was particularly curious for analysis at James Madison University by Lance Kearns. One was the "satin spar" like material, which Kearns identified as pokrovskite. He also uncovered another brown and radiating mineral from the rosasite series that he could not identify. The possibility seems realistic that this could be a new mineral. To date, no one has come forward to probe further regarding its possible submission to the IMA for approval as such.

And now for the bad news: Prospects have been quashed at Hunting Hill for collecting any more pokrovskite, any more of this potential new mineral, or for that matter any of the 70 species known to occur there. A Swiss company recently purchased Hunting Hill and closed it to all with interest in collecting.

Saturday, March 6, 2010

Philadelphia Academy's Maryland Mineral Suite Comes Home

I find myself coming up with words like "heinous" and "ignominious," when contemplating how for more than 50 years the Academy of Natural Sciences of Philadelphia ignored and neglected a significant national treasure that happened to be its mineral collection . Over that period, a fair number of the 30 thousand plus specimens therein had decomposed, were pilfered, or crashed into one another amidst rotting storage facilities. Finally, in the early part of the "aught" decade, the Academy decided to sell. John White, former Curator of Minerals at the Smithsonian, wrote in a subsequent digital commentary, that the Academy's then president "was dazzled by dollar signs." The sale took place in 2007.

With no other museum able to afford to purchase so vast and important a collection, it ended up in the hands of two prominent high end mineral dealerships, namely Collectors Edge and Cristalle. Both entities have long been highly regarded and well respected by pretty much the entire gamut of players in the mineralogy arena. Their stewardship and disposal of the Philadelphia Academy collection has lived up to that reputation. Various "suites" of minerals sorted according to locality were kept together and offered for purchase to museums and other potentially appropriate custodial sources. The Carnegie Museum in Pittsburgh, for instance, purchased the entire Pennsylvania suite of over 400 flats.

The collection had a vastly smaller Maryland suite, in which no educational institution or museum demonstrated interest, perhaps because few of the Maryland specimens rated as "eye candy." That was fine with Marylander Fred Parker, to whom vintage minerals had just as much appeal. After making inquiries that were followed by words on his behalf from friends, Parker ultimately received a phone call from Steve Behling of Collectors Edge.

Negotiations were simple and quick. With low demand, the price was right, and Parker accepted Behling's offer without a haggle. Arrangements were made for delivery and transfer at the 2008 East Coast Gem and Mineral Show in West Springfield, Massachusetts.

Since bringing the suite home, Parker has kept it completely intact. The best pieces fill the case by which he stands in the picture (at top)/ He keeps the others in two flats next to it.

"The labels," he notes ( meaning additional labels accompanying the Academy's labels), "are a who's who of the important mineralogy people of the 1800's." The names include Gerard Troost (1776-1850), William Jeffries (1820-1906), and Horace Hayden (1769-1844). On the label next to the smoky quartz crystal at left, the early collector's name (George Carpenter (1802-1860) has disintegrated away. The locality, Frederick County, with no information as to exactly where in Frederick County, is still legible. That's how it was in the 1800's Fred explained to me. The labels back then were less specific about localities than they are today.

Another mineral from the suite that especially impresses Parker is a magnetite crystal from Harford County that's just short of two inches in diameter. He also particularly likes, more for its unusual combination of minerals than appearance, a specimen of sphene with tabular apatite crystals and plates of hematite.

Credit Fred Parker for preserving a meaningful and pertinent part of history that would otherwise have been lost. This vintage suite of minerals not only chronicles the evolution in Maryland of a scientific field of study, it tells us what the State is made of.