Tuesday, April 19, 2016

The Carroll Mine in Carroll County, Maryland




The Carroll Mine was one  the four largest 19th Century copper and iron mining operations to exploit Carroll County, Maryland’s Sykesville Mining District. Worked intermittently between the 1840's and 1880, it appears to have received the least attention over the years from the mineralogy community. The copper and iron  bearing species from all four major mines in the District  were much the same. Cobalt-bearing  Linnaeite Group species occurred at all four mines, though not in sufficient quantity for successful commercial production. 
   
We are grateful to Stuart Herring, a prominent Baltimore-based collector and dealer, whose research led us to the several pits and grown over dumps from these Carroll Mine workings. While trails lead to the only other two mining areas that still exist in the Sykesville Mining District, a substantial bushwhack is necessary to reach the mostly grown over remains from the Carroll Mine.

The Carroll Mine hosted two separate operations at different time periods. Though primarily a producer of iron, at least one shaft was worked for copper by the New Burra Company. The material on the surface around the pits and near the dumps varies. Specular hematite and magnetite are quite easy to find.  Near one of the shafts, most likely the Burra Shaft, are sizable chunks of crystallized epidote, stressed massive garnet, and magnetite. All three host an abundance of copper bearing minerals.

 




Magnetite---ore quality:








Bornite---ore quality.







Chysocolla is abundant amidst the copper bearing minerals and ranges in color from a pale blue-green to a vivid medium blue.








Lesser quantities of malachite sometimes accompany the chrysocolla, often in small green crystal sheaths.






Chalcanthite and melanterite appear to the naked eye as earthy pale blue crusts hinting at  microscopic crystals, The crystallization becomes clearly evident under the scope. The two species can often be difficult to visually distinguish from each other.



Pyrite and chalcopyrite were present, but not as prevalent as at the Springfield and Mineral Hill Mines. We did not find any cobalt bearing linnaieite-siegenite-carrollite material .

Although native gold has not been reported from the Carroll Mine dumps, we kept our eyes peeled for it. Throughout the area was a fair amount of  white quartz that was weathered in a distinctive manner.  It visually  resembled quartz that once yielded a few  gold particles at an isolated nearby pit, long since built over. .

Wednesday, March 23, 2016

Greenbelt, Maryland’s Phosphate Concretions: 75 Years of Questions



We are grateful to John White and Marie Huizing for procuring  two photocopied articles from 1965 editions of  Rocks and Minerals. The first article is entitled “Unusual Mineral Locality at Greenbelt, Maryland” by French Morgan; the second is a follow-up article Dr. Ernest E. Fairbanks, entitled “Remarks on an unusual mineral locality at Greenbelt, Maryland .” The information in these articles proved essential for this post.

Maryland’s only significant phosphate mineral find resulted when in 1941, a knoll  was leveled in order to erect a WWV Broadcasting Station near Greenbelt, in Prince George’s County. Today, the Visitor Center for the NASA Goddard Space Flight Center stands directly on the site.  The above pictured image shows one of many unearthed phosphate-bearing concretion nodules that were collected there in the 1940’s.

It is notable that iron bearing sandstone concretions of similar external visual appearance are common in Prince George’s County northeast of Washington, DC.  However, the only phosphate mineral bearing concretions ever known to occur in the region are from this one specific locality.

Out of curiosity, the late Dr. E. E. Fairbanks of the U.S. Bureau of Mines procured a few of the concretions for examination. The verdict, presumably based on visual observation, was that the phosphate material was dufrenite.  Dr. Fairbanks then provided a number of concretions to Ward's Natural Science Establishment, which subsequently sold them to various dealers and collectors labeled as dufrenite . Some concretions also found their way to both the Smithsonian Museum of Natural History in Washington, as well as the American Museum of Natural History in New York.

During World War II, the U.S. Government closed the area around the towers to the public for safety reasons. However, by 1944, French Morgan and several other members of the Mineralogical Society of the District of Columbia obtained special permission to collect there.  The group collected several dozen concretions that apparently had rolled down a small hill from where grading for the radio towers had taken place. Some of these concretions proved to be more interesting than those found several years earlier.

 In his 1965 article in Rocks and Minerals Morgan mentioned finding limonite, goethite, opal (var.) hyalite, and beraunite  during these later 1944 visits as well as “red, yellow and white minerals as yet unidentified.”  He also   noted “shrinkage cracks lined with microscopic crystals of an unknown mineral.” Specimens of the crystals were submitted to the U.S. U. S. Geological Survey, where according to article they “created no excitement.”

Not until late 1949 or early 1950 did the U.S. Geological Survey become interested in the Greenbelt material. This was after and was probably prompted by a 1949 article in American Mineralogist  by the late Dr. Clifford Frondel entitled “The Dufrenite Problem.” Frondel's work  confirmed that after analysis, the material from the original 1941 find at Greenbelt  was in fact rockbridgeite rather than dufrenite. The article described rockbridgeite as “indistinguishable from dufrenite in its general appearance and confused with that species since earliest times.” Later in the article, Dr. Frondel went even further to refer to rockbridgeite as “identical in appearance with the fibrous varieties of dufrenite.”

Soon thereafter, the U. S. Geological Survey reported x-ray and chemical analyses of a new and unknown species from within Greenbelt concretion material. Subsequently, a new revision in Dana noted that a similar mineral had been found in Russia. A brief description concluded that additional verification was needed.  The new Russian find received the name avovskite.  More than a decade after this Russian discovery and in the midst of the Cold War, Morgan’s article in Rocks and Minerals article noted that “attempt (to obtain more information and/or a sample)  has been made through diplomatic, scientific, and other channels, but no trace of azovskite has been unearthed.”

 Morgan also claimed in his article that “at the very beginning,” he had been promised naming rights from an unnamed source should a  new species be uncovered. He suggested the new mineral be named named fairbanksite  (not to be confused with the lead tellurite fairbankite ) in honor of Dr. Fairbanks. The only reference to fairbanksite we have been able to locate is on Mindat, which describes it as “unidentified microscopic crystals in shrinkage cracks in concretions,” citing Hey’s Chemical Index of Minerals, 2nd Edition 1962.

Even today, the IMA describes the status of azovskite as “doubtful.” Fleischer's Glossary of Mineral Species (2014) does not mention azovskite; nor does either edition of Bernard and Hyrsl's Minerals and their Localities.   Mindat states that azovskite “appears to be a gel” and “may be identical to delvauxite.” Delvauxite, however, is amorphous and is not known to replace crystals of other species,  Still, it is interesting to note brown globular material appearing in shrinkage cracks of Greenbelt concretions that bear a visual resemblance to delvauxite. Delvauxite is not known to have been reported from Maryland.

Catalogued in the Smithsonian collection are numerous “azovskite” specimens, mostly from Greenbelt. The catalog states or implies that none of the specimens was ever x-rayed. A curious and lengthy PDF procured from the Internet describes azovskite as a mixture of  santabarbaraite and goethite.  Also observed on the Internet was an azovskite specimen from Hagendorf, Germany, offered for sale by a European dealer who described it as santabarbaraite and goethite on quartz.  For santabarbaraite to be replacing crystals of goethite hardly seems a stretch. In fact, one of the Greenbelt azovskite specimens catalogued in the Smithsonian collection names goethite as an associated mineral. Santabarbaraite, on the other hand, has never been reported from anywhere in the Americas, much less Maryland. Just as interesting is that the Smithsonian collection catalog gives the Crimean Peninsula as the locality for one of the azovskite specimens.  According to Mindat, the Crimean Peninsula boasts five santabarbaraite localities, far more than any other region or country on earth where santabarbaraite is known to occur.

After  Rocks and Minerals published Mr. Moore’s article in 1965, Dr. Fairbanks submitted his follow-up article entitled “Notes on the unusual mineral locality at Greenbelt Maryland,” In addition to gratefully concurring with Mr. Morgan’s nomenclature  suggestion, Dr. Fairbanks  raised an additional point that 37 years later would prove eerily prophetic. He stated:  

It is definitely odd that the small area in which the rockbridgeite concretions were found was the only one in that area where phosphorous was relatively abundant. A very prominent non-government geologist suggested that a huge dinosaur died here furnishing the phosphorous.  

In 2012, Smithsonian.com  published  that the well-known local amateur geologist and fossil hunter,  Ray Stanford, was instrumental in the discovery of two nodosaur tracks on the property of Goddard Space Flight Center. A heavily-armored plant eater, the species was known to reach the size of a small elephant. It received its name from the numerous spikes in its armor. Stanford uncovered the tracks during excavation for the new building pictured at left, photographed from the immediately adjacent Goddard Visitors Center. 

The most recent published research regarding the Greenbelt concretions appears in Lawrence R. Bernstein’s 1980 Maryland Geological Survey Publication Minerals of the Washington, D.C. Area, which evolved from an earlier 1975 U.S. Geological Survey Professional Paper (Volume 475, parts 1-4) by Mr. Bernstein. Therein Bernstein noted oral communication from  Mary E Mrose of the U.S. Geological Survey reporting  cacoxenite, lipscombite, phosphosiderite, and strengite in the concretions. Our research turns up no other evidence that lipscombite, phosphosiderite, or strengite were ever reported from Maryland. The same can be said for the beraunite that Morgan claims to have collected between 1944 and 1949.

Hopefully, there are facilities willing to provide further analyses. The possibility of a new mineral species being discovered  in Maryland would surely be significant. Maryland’s only other type locality mineral---for which no type specimen is known to exist---is carrollite, discovered  at the Patapsco Mine in Carroll County and named in 1852. Should analysis of any Greenbelt “azovskite” specimen reveal santabarbaraite, America’s first santamariaite find would similarly be serious mineralogical news.  And confirmed analyses of lipscombite, phosphosiderite, strengite, or beraunite would be a major contribution to what is known of Maryland’s mineralogy.   

Sunday, February 21, 2016

In Memorium: Harold Levey: (1925-Feb.8, 2016)


With great sadness we mourn the passing on February 8, of Harold D. Levey  in Baltimore County's Northwest Hospital due to complications from a fall several days earlier. Liked and admired by all who knew him, Harold could be considered the patriarch of Maryland mineral collectors, not only by virtue of his age, but by the breadth of his experience.

Locally, that experience dated from when Baltimore City's Jones Falls pegmatites were accessible and in Baltimore County, both the Bare Hills Copper Mine and the the Bare Hills Chrome Pits yielded rich specimens. He collected also at the McMahon and Texas Quarries in Baltimore County when they were known respectively as the Greenspring Quarry, and the Campbell Quarry. He spent a lot of time at the Fairfax Quarry in Centreville, Virginia, when its management actually permitted overnight camping. The Smithsonian once traded him an African mimetite specimen for a classic Centreville apophyllite on prehnite piece that it prominently exhibited for years.  Harold's local and regional collecting experience contributed to and was later enhanced in 1955 by a six month trip to numerous localities throughout the United States.

Natural history fascinated Harold from when he was a child. While looking for snakes at age 14, he extraneously uncovered the above pictured curved Tourmaline Group (var.) schorl  crystal in quartz. The experience led to his subsequent focus on mineralogy. Curiosity about the find prompted a visit to the Natural History Society of Maryland to seek out someone to identify the specimen. As a result, Harold donated it to the Society’s collection and became active as a member. When Charles Ostrander, NHSM’s  original mineral curator moved to Harford County around 1950 Harold became de facto curator.

It was during this period, when Paul Desautels, then a professor of chemistry at the Maryland State Teacher's College (now Towson State) showed up to view the NHSM collection. That visit led to the formation of the Baltimore Mineral Society. Along with  a small group including  Mr. Desautels and John S. White, both future Curators-in-Charge Gems and Minerals at the Smithsonian,  Harold became a founding member and later  president. 
Harold continued to remain active with the NHSM late into the 1950’s.  NHSM then sponsored a Junior Natural History Society of Maryland. Throughout his life, Harold believed strongly that the best way to perpetuate the hobby of mineralogy was to have youngsters participate. He frequently led field trips for Junior NHSM members to a range of localities. They included visits in Carroll County to the Mineral Hill Mine, as well as a long built over cornfield loaded with quartz crystals near Gamber. He also led more distant trips to the dumps of the Cornwall Iron Mines in Lebanon County, PA, and the Showalter Quarry in Lancaster Co. PA. 

Like so many collectors Harold’s life during late middle age centered on family and work: wife Margie, their daughters Dana and Jodie, and a career as quality control manager for AAI Corporation at Hunt Valley in Baltimore County. Deeply saddened by Margie’s death in 1990, he became less active with mineralogy. However, his interest in minerals remained. He maintained his collection until 2013. That summer, failing health necessitated a move from his home near Pikesville to the nearby North Oaks Retirement Community. 

Further perspective on Harold Levey’s role and stature within the mineralogical community is available at the  Mineralogical Record label Archive:  http://www.minrec.org/labels.asp?colid=598 .



Saturday, January 30, 2016

A Plea to the American Museum of Natural History

Were the images larger, or had we photoshopped them a bit, you could read the labels. Clockwise from far left, they read as follows: Boleite, Cottenite, Cumengite, Laurionite, Diaboleite; and  Matlockite. They are are some of the more aesthetic  systematically classified halides on exhibit in the Amercan Museum of Natural History's Harry Frank Guggenheim Hall of Minerals. While not included on the labels, their localities and chemical composition formulas are shown nearby. With sufficient lighting, that information and the specimens themselves would surely attract a higher level of interest from viewers .

A forum on Mindat entitled "Does anyone else think the AMNH displays are lacking?" spans several pages of opinions, most from well-known and highly respected mineral aficionados. The descriptions include "Dowdy;" Disgraceful;" "A bummer to look at;" "Tragic."  Poor lighting is by far the most frequently mentioned deficiency. 

The lighting is so bad it renders many minerals unrecognizable to the point that they offer little in the way of education or entertainment. Particularly notable in this regard are some of the rarer species present in relatively minor proportion on much larger rocks. Where, for instance, is the whitlockite in the specimen pictured at right? Blown up and brightened with appropriate digital photography software, a milky colorless tabular crystal of about a centimeter in width is visible at top right. It's  an inordinately large crystal for this rare phosphate species. However, insufficient lighting renders the whitlockite invisible. And even with decent lighting, a written description regarding its presence would be necessary for the vast majority of viewers to notice it.

Comments on the Mindat forum offer plenty of opinions as to why the AMNH exhibit is so inadequate. They range from funding issues to bureaucratic red tape. One comment surmised that the AMNH directors disparaged minerals "because they were never alive."

Another recalled the world class mineral collection  that was neglectfully stored away at the Philadelphia Academy and all but forgotten. After many years, the directors of that institution  decided to sell what was left of the collection to  dealers who at least were able to bring the specimens into circulation for people to appreciate.

It is unfortunate that the world class  "Spectacular Stibnite" specimen in a well-lit area outside the the Hall of Minerals beckons those who see it to enter. Upon doing so, they soon observe a large display of mind-blowing native gold specimens from California. The lighting for them is substantial, but fails to present as realistic a visual perspective of these treasures as would a different lighting scheme.  And from here, it all goes downhill.

The AMNH's Financial Statements are available on line along with the names of those on its Board of Trustees. Does anyone on this board appreciate or understand that minerals should be viewed in a manner where it's possible to better appreciate them? If they are to remain in a dark room they might consider for perspective a visit to the the Hillman Hall of Minerals and Gems at the Carnegie Museum of Natural History, or the Cullen Hall of Gems and Minerals at the Houston Museum of Natural History. And should it make sense to light the entire room, they might check out the wonderful Smithsonian Natural History Museum. Something major needs to be done  to remedy the situation.


Sunday, January 3, 2016

Bounty of Baltimore County's Texas Quarry

Look  to the right heading north on I-83 between Padonia and Warren Roads. Where not obscured by embankment, you glimpse the enormous Texas Quarry. As one of five Maryland aggregate quarries that Bluegrass Materials purchased in 2014 from LaFarge North America, this ever growing pit has yielded dolostone for various purposes since well before the Civil War. Its length extends for a mile in places, and it penetrates the Cockeysville Marble formation to a depth of more than 500 feet, well below sea level. Over time, it has yielded a range of mineralogically interesting material, most that was collected decades ago ,
Arguably, the Texas Quarry is best known for its dravite, a tourmaline species, which occurs as adamantine crystals in white dolomite and calcite. The above specimen is from the collection of John S. White, past Curator-in-Charge of the Gem and Mineral Collection at the Smithsonian.
Despite its place in the Mica Group, phlogopite can visually resemble dravite. Sharing similar color and adamantine luster,  phlogopite is ubiquitous at the Texas Quarry. The above pictured piece could be the most collection-worthy Texas Quarry phlogopite piece  known to exist. It is a true Maryland classic that was pictured in  Ostrander and Price's Minerals of Maryland (Natural History Society of Maryland, 1940), and is currently owned by Baltimore area collector Bob Eberle.
Scapolite Group species and varieties, often simply labeled as wernerite, have always been a special find. Regardless of nomenclature, if the color is lilac, it's  a Texas Quarry treasure. We acquired the above pictured specimen from the late Baltimore County dealer and collector Larry Krause. The historic Natural History Society of Maryland label that accompanied it noted that it was collected by the late Charles Ostrander, co-author of the aformentioned book.
Never plentiful, most Texas Quarry Scapolite Group material featured greenish gray crystals. This 4.3 cm. crystal is a fine example. Particularly impressive is the pinkish lavender fluorescence of the accompanying calcite.




Relatively little Texas Quarry calcite fluoresces..As attractive as the above specimen appears, we've observed little  to be as  collection worthy as crystals from other well- known Maryland localities.

Rutile in crystals of more than a few centimeters are rare. The well-known Maryland collector Fred Parker collected this 1.6 cm. long crystal in the 1990's
Neither sphalerite nor baryte are particularly common here.  However, they are  notable when associated with each other as shown above along with some dolomite in the mix.
Little if anything relating to the occurrence of  bornite is in any of the literature we've been able to access. Nor has there been mention of chalcopyrite. That Fred Parker's sharp eye spotted this bornite specimen does not surprise us. We managed within a few seconds to observe chalcopyrite in dolostone boulders piled up near the Bluegrass Texas Quarry sign when shooting our title picture.  
The chalcedony in calcite, as pictured above proved to be eminently collectible.
We saved the image of Texas Quarry  pargasite for last.  Another Fred Parker find, it is the only example of this species of which we are aware from  the Texas Quarry or any other locality in Maryland, except for the Hunting Hill Quarry in Montgomery County.

Other species known to occur at the Texas Quarry are as follows :pyrite, tremolite, pink dolomite, wollastonite, fuchsite, purple fluorite, dendrites (probably manganese oxide), galena, pyrrhotite, quartz, sphene, talc, chlorite, molybdenite, margarite, diopside, and asbestos.

AFTERWORD

Before posting  we contacted Fred Parker in New Mexico to conifrm that he had not only provided but  personally field collected the pictured bornite, rutile, and pargasite as noted.. After confirming this, he shared two facinating remembrances
  • A specimen from a find circa 1935 labeled "sphalerite on limestone." 

Associated with dolomite crystals,they are stacked hexagaonal plates that appear to be sphalerite. I believe these are sphalerite after wurtzite paramorphs and good ones at that. Fred recalled  where this specimen was housed when he observed it. If still in the same collection and access can be arranged, we'll cover it in a subsequent post. 

  • AMAZING  DRAVITE 

I also recall in the early-mid 1990's a blast in which a boulder at the base of the rubble pile contained the best dravites I ever saw from Texas, as I recall 3 to 4 inch crystals. They could not be safely recovered so went to the crusher. 



Sunday, October 4, 2015

A Serious Agate Find in Baltimore County, Maryland




Definitive banding and translucency are disinctive characteristics of  the only true Maryland agate find of which we are aware.  The locality appears to be around a contact point  between siliceous (quartz) rock and  serpentinite  rock within a small  plot between I-70 and  Catonsville where a Baltimore County geological map shows serpentinite to be dominant.

The metamorphosed quartz rock is rich in iron. Drusy quartz, often nodular, is frequently present, often on the surface of these rocks, and it fills vugs  inside them.  Banding is occasionally apparent, especially inside the particularly vuggy rocks.   Much of the material is similar to that collected half a century ago during the construction of I-70. The specimen pictured at right, which well-known Baltimore County collector Bob Eberle brought home from I-70  in the late 1960's, boasts  coatings of opal (var.) hyalite.

Shown at left is an example of the more recently discovered material before  being sawed or polished. When viewed under the scope, its banding appears as minute vugs filled with an iron rich quartz druse and other ferrous material as pictured in the   photomicrograph at right.



 A clearer macrocrystalline quartz druse accounts for  the translucency evident on  polished slabs as well as blue to
purple banding  in the images beneath our title post. This becomes evident when viewing the photomicrograph at left, which also suggests that the green color could bespeak sand grains at early stages of tectonic compression.

A potential for questioning the legitimacy of agate nomenclature asserts itself in various official definitions that specifically categorize agate as cryptocrystalline  with conchoidal fracture.  While a limited amount of chalcedony is present in a few of the Baltimore County specimens as shown at right,  most are primarily  quartzite with a healthy presence of macrocrystalline quartz.

 For clarification, we contacted John S.White, Past Curator-in- Charge of of the National Gem and Mineral Collection at the Smithsonian as well as one of the world's most frequently published authors on questions relating to the integrity of species nomenclature. His response:
 I have seen lots of agate boulders split without them exhibiting conchoidal fracture.  However, a chip from them might well do so.  In any case, if this is quartz and it exhibits colorful banding, then I see no problem with calling it agate.  Lots of agate has bands that are colorless quartz xls, especially on the inside of nodules as the very last thing to grow.  Quite often “agate” is in the eye of the beholder and lots of stuff that you nor I might not care to call agate is called agate by those who have it.  This material does appear to be banded and very colorful and I would not mind having a cab of it myself.

Clearly, the banding and the translucency define the material as agate. They also raise questions relating to Maryland's Official State Gemstone, known as "Patuxent River Stone" and described on the State of Maryland's Kid's Page as follows:
The Patuxent River Stone is actually an agate, a cryptocrystalline form of quartz. Found only in Maryland, the Patuxent River Stone's  colors of red and yellow reflect the Maryland State Flag. 
 Patuxent River Stone, of course, is neither banded nor cryptocrystalline. Even worse, until after the publication of our previously referenced post about Patuxent River Stone on October 29, 2010, it  was still being called"agatized dinosaur bone”  as well. In truth, Patuxent River Stone is nothing more than quartzite with some red and yellow hues.


Wednesday, September 9, 2015

A Major Quartz Crystal Find in Baltimore County,Maryland

During the past year as construction crews were clearing and digging, the now  built over and/or  grown over and off-limits construction site pictured above  near Owings Mills was the site of what could have been the State of Maryland’s most exciting and prolific quartz crystal bonanza ever.  For those with permission to collect and who knew what they were doing, the former construction site yielded notably diverse milky, clear, smoky and amethystine quartz crystal specimens including small clusters and individual crystals, most that were  doubly-terminated, and some with  Cumberland habits as well as a few scepters.

Members of the Chesapeake Gem and Mineral Society, the Baltimore Mineral Society, the Gemcutters Guild of Baltimore, and others  collected  tens  of thousands of quartz crystal specimens. The crystals displayed  by Mark Ruzicka, a Catonsville home improvement contractor pictured with his son Mason and daughter Ashley, bespeak but a fraction of the quantity of specimens they collected in just over a year. Prominent Baltimore County collectors Bob Eberle and Bernie Emery,  the a latter who first informed  Mineral Bliss of the find, collected nearly as many.

Richard Hoff, the immediate Past President of the Chesapeake Gem and Mineral Society, who is pictured at right exploring a crystal pocket, estimates that he collected about 30,000 specimens. Everyone  agrees that the kinds of crystal specimens they fsound changed through different stages of work by an accommodating construction crew.

In the early spring of 2014, the removal of trees from the site uncovered huge quartz boulders bearing numerous milky quartz
crystals. By late spring,  construction crews had removed enough earth to level the entire area, piling the dirt into a mound about 30 yards long,  8 yards wide, and  5 yards high. From these mounds, collectors uncovered plates of quartz bearing multiple crystals measuring to well over an inch. Most of these crystals were milky, some of them clear. Encrustations of dried clay were present on many of the specimens. A different mode of collecting began to evolve around the Fourth of July.

Richard Hoff was there the day that Jim Hooper, President of the Baltimore Mineral Society, wandered a few yards south from the dirt mound and found a single doubly-terminated quartz crystal measuring about an inch and a half. It was embedded in a two foot embankment where a road would later be cut. Almost immediately, Hoff and the other collectors who were present began digging a short distance from the embankment and eventually found more crystals. They dubbed the hole that produced them as “the Hooper pocket.”

In the Hooper pocket and various other holes that struck pay dirt, they typically first encountered small plates of crystals about a foot beneath the surface. As they dug slightly deeper. they found more clustered and individual  crystals.  Some of them hinted at the potential for star patterns as portrayed in the amethystine crystals pictured at left  . Hoff referred to them as “spider legs.” Lots of smokies were in the mix.

Many crystals appeared at first to be floaters. Upon close examination, however, contact points became evident, except where weathered away.  The image at right from a plate of scepter-like crystals provides a hint as to where and how many such crystals could have originated.

The site is near the southwestern edge of a gneiss formation known as the Chattalonee Dome that extends west from Falls Road to about a mile north of Randallstown. In that same area,  a  Johns Hopkins foliation and bedding map of the Chattalonee Dome shows in the general area of the crystal pockets two small patches of fault breccia that is consistent with the micaceous dirt and clay from which the crystals were extracted.  Hoff theorizes that over hundreds of millions of years, both liquid siliceous material and fault breccia filled pockets where feldspar from the Chattalonee Dome gneiss had deteriorated and that crystals began to form that later experienced numerous stages of growth. He suggests that interference from fault breccia material, which also displayed a significant presence of iron (goethite, limonite, and pyrite in specks and tiny crystals) could have accounted for the "spider leg phenomenon. Pictured above at left is one of his less common finds: a golden pyrite cube included within a clear quartz crystal.

Hoff’s  thoughts regarding the science behind these  Owings Mills crystals speak for an innate curiosity and a passion for collecting. Like most who became fascinated with these crystals, he believes that the locality deserves study in academic circles. The opportunity is more than available with the myriad   crystals that Hoff, Ruzicka, and so many others have saved.  Both Hoff and Ruzicka can be reached by email to provide specimens.