Tuesday, July 16, 2019

Pink Quartz, not Rose Quartz in Harford County, Maryland



The question is whether the above pictured image is actually rose quartz. This writer collected it in Southeastern Harford County, Maryland. Rose quartz has never  been officially identified and verified as occurring in Maryland. 


Numerous well-versed regional authorities who viewed this specimen have given different reasons why they believe it is not rose quartz. While most of them were credible, none were scientific. “You could call it rose quartz" was as close as any response came to a confirmation of rose quartz. However, it went on to note: "It's just not quite the right color.” 

The genuine rose quartz specimen  at left was placed amidst a varied  assortment of quartz cobbles and pebbles that members of a family collected in the woods behind their house. On a recent visit, the specimen in our title picture turned up after we had spent about 15 minutes turning over rocks in their woods. It visually resembled the uncontested rose quartz specimen as much as any of the previously collected pieces shown at right. 

The locality is a wooded area to the southwest of Rt. 152 about 2 1/2 miles northwest of I-95. It is at a point where Maryland's Coastal Plain intersects with its Piedmont. Small cobbles of quartz and quartzite  along with a few less distinctive metamorphic rocks are ubiquitous underfoot. Nearly all of the quartz and quartzite show color: red, yellow orange, brown, and ---yes pink. These colors result from a presence of iron oxide, typically hematite, that has stained the quartz and has often become included within as the quartz formed millions of years ago from a complex sequence of geological events. 

By the standard definition, rose quartz owes its color to inclusions of crystals of one, possibly other minerals within the quartz. Staining is never a factor. The inclusions are separate, miniscule and all but impossible to separate so that  analysis of them by x-ray diffraction is rarely possible.

Mindat cites two studies stating that massive rose quartz always has a "hazy to translucent character due to microscopic fibrous inclusions of a pink borosilicate mineral related to dumortierite." The likelihood is all but nil that inclusions of such a species, which is not known to occur in Maryland, would show up within quartz pebbles exclusively in an area where most of the quartz shows iron oxide staining and/or inclusions. Without analysis or a nearby presence of verified rose quartz, a better option is to call the material “pink quartz.” 

It takes a good polish, has more variants, and can be just as pretty.




Thursday, July 19, 2018

Baltimorite


Pictured above is a specimen of serpentine collected circa 1940 at the chromite bearing serpentine barrens of Bare Hills in Baltimore County, Maryland. It is one of several such specimens The Natural History Society of Maryland owns. Very likely Charles Ostrander and/or Walter Price, the Society's  prominent curators at the time, collected them. The NHSM labels identified the specimens as  "baltimorite". Minerals of Maryland, the NSHM publication that these two curators co-authored in 1940, may have been the last regional publication to suggest that "baltimorite" was  a species or variety of a species.

 Mindat describes  baltimorite as a "synonym for antigorite." along with 11 other names including "gymnite" and "porcellophite." Interestingly, Minerals of Maryland refers to "gymnite" and "porcellophite" as separate minerals that also occur,  along with "baltimorite," at Bare Hills.  The three names  have since all but disappeared from mineralogical parlance, although  Bernard and Hyrsl's Minerals and Their Localities refers to gymnite as a synonym for deweylite,  which is typically identified as a mixture of several varying different species that can occur  together at some of central Maryland's serpentine outcrops.

In addition to naming twelve antigorite synonyms, Mindat also names eight varieties of antigorite. Two of them, williamsite and chrome antigorite,  are known to those who collect in the serpentinized areas of Central Maryland and Southern Pennsylvania. Highly valued  in lapidary circles, williamsite is  best described as a  solid and translucent apple-green antigorite included with specks of black chromite. Chrome antigorite displays varying amounts of reddish purple coloring attributed to the presence of chromium. It is usually columnar or fibrous and known to occur primarily at the now off-limits Woods Chrome Pits in Lancaster County, Pennsylvania  just a few miles north of the Mayland state line.   

Antigorite, lizardite, and chrystotile are the best known of 13 species in the serpentine subgroup. In addition to these 13 species, the serpentine subgroup as an entity boasts eight varieties, none of them approved as species in their own right.

 One such serpentine subgroup varietiy is picrolite. Mindat defines picrolite primarily by habit  as "a columnar or coarsely fibrous (non - asbestiform) variety of serpentine commonly referred to as a variety of antigorite, but may be other species." The most common of these "other"  species are the serpentine subgroup mineral species lizardite and chrystotile. Picrolite is ubiquitous at nearly all the serpentine exposures in central Maryland and southern Pennsylvania. Note the label on the NHSM specimen at right : "Serpentine, var. baltimorite (Picrolite). It makes sense. Here it can be assumed that the term picrolite was used to to refer to the columnar habit of the sample.  The original material that was given the name baltimorite in 1843  and  wherever else the name was used thereafter matched the Mindat description of picrolite. Typically the color of picrolite is green as shown in the image at left. Interestingly the color of  the several "baltimorite" specimens at NHSM---which are the only specimens anywhere so labeled that we are aware of--- is  brown.  Would it be unreasonable to colloquially refer to picrolite of brown color as "baltimorite?" An interesting aside is that the approved species known as "chrome antigorite," like picrolite, is almost always columnar.

It was Thomas Thomson, a British mineralogist, who came up with the name baltimorite in 1843 (Phil.Mag.22, 1911). He had recently received a specimen from the well-known American scholar and collector Francis Alger. Collected at Bare Hills in Baltimore County, the specimen was opaque with a silky luster and consisted of longitudinal fibers that adhered to each other. Alger had referred to the material as "asbestos and chrome."Thomson studied the specimen. After ruling out the presence of asbestos as well as chromium, he named it baltimorite for the locality.

Two  years later, citing Peggendorff's Annals, Vol. lxii, p. 137, The Edinburgh New Philospophical Journal, Volume 39 published in an article that the German mineralogist Karl Friedrich August Rammelsberg had found that Thomson's "baltimorite" was identical  to other material that had  become known as chrysotile by Kobel.  Franz Kobel  was another German mineralogist, who had originally called the material Schiller asbestos. The conclusion: "As the latter (baltimorite) was described subsequently to the former, the name of baltimorite must be given up."

However, the baltimorite handle endured, only to receive an additional blow in 1855 by a supplement to Dana's The System of Mineralogy. Therein it was noted that two years earlier,  the German mineralogist C. von Hauer had published a new analysis of purported baltimorite in which the chemical composition varied from the original composition given by Thomson. The Dana supplement concluded: 
We have a new analysis of a stone which somebody has labeled baltimorite. It is very wide from the original baltimorite of Thomson (from Bare Hills, Maryland) and is no better entitled to the name than many other fibrous stones that could be gathered from our serpentine regions.
 Eighty one years later in 1936, the American Mineralogical Association placed the final nail in "baltimorite's" coffin. The American Mineralogist in an abstract of a paper by George C. Selfridge, Jr.  of Columbia University entitled "An X-ray and Optical Investigation of the Serpentine Minerals" proclaimed on page 463:
Based on the results of the x-ray and optical studies and the chemical discussion---to drop the names picrosmine, picrolite, williamsite, bowenite, porcellophite, and baltimorite  for the term antigorite. The term serpentinite is suggested for rocks composed of serpentine or antigorite or a mixture of both. 
The recommendation came at about the same time as the mineral aficionados at NHSM were collecting and labeling "baltimorite" specimens from either Bare Hills or the geologically similar Soldiers Delight serpentine outcrops, also in Baltimore County. Interestingly, the NHSM labeled as "picrolite" numerous specimens from serpentine outcrops in Maryland's  Harford County that appeared to differ from those labeled "baltimorite" only by their green color.

Then in 1956, in Vol. 41 of  The American Mineralogist,  a 21 page paper by George T. Faust and Bartholomew Nagy outlined studies showing "that minerals classified as serpentines are either chrysotile,  antigorite, or natural mixtures of these two minerals--- It is suggested that serpentines should be redefined in terms of the relative proportions of antigorite and chrysotile"

Notwithstanding, the endless questions, answers, and names involving  various species and varieties in the Serpentine Subgroup have continued---and undoubtedly will continue--- to evolve without reference to baltimorite  For now, here is the best definition for baltimorite we've been able to come up with:  an obsolete and antiquated synonym for picrolite, a serpentine group variety, which depending upon composition may actually be antigorite, lizardite, chrystotile, or a combination of them.

We are grateful to John S. White, Past Curator in Charge of the Mineral and Gem collection at the Smithsonian's National Museum of Natural History for suggesting this story, turning us on to some of the referenced sources, and proofreading it. 
  

Wednesday, March 7, 2018

Leesite: Another New Species Discovered by Patrick Haynes


Leesite

Patrick Haynes
In  1989, Patrick Haynes collected what 27 years later would become the new uranyl oxide micromineral leesite. Its locality is the Jomac Mine in White Canyon, San Juan County, Utah.  It is the locality, where at about the same time, Haynes  discovered two similarly rare and microscopic uranium bearing species, blatonite and oswaldpeetersite.   The name leesite is eponymous with Brian Lees, the legendary owner of Collector’s Edge.

Soon after collecting it, Haynes examined material under the microscope and assumed that it should be an identifiable species. The orange color led him to suspect it to be fourmarierite or curite. He submitted it to Dr. Michel Deliens at the Royal Belgian Department of Natural History in Brussels, Belgium along with other material, which the International Mineralogical Association (IMA) would later approve as blatonite and oswaldpeetersite.  The verdict on the future leesite suggested that it was a combination of species.

Ten to fifteen years later, Haynes learned about success at identifying difficult new species by  Dr. Frank Hawthorne, Professor of Mineralogy and Crystallography at the University of Manitoba.  He sent a sample of the orange unknown material to Dr. Hawthorne to examine. Like the scientists in Brussels, Dr. Hawthorne believed it could be a mixture, but this time of a different combination of minerals.   

Haynes  explained:

Leesite is very fine-grained, and it is commonly associated with another orange potassium uranium oxide called compreignacite, which can make sample preparation very difficult. With the few "coarser" crystals one can generally make a visual determination, but that is unusual.

A few years later Pat became aware that Travis Olds and Tony Kampf had been “working up these ridiculously tiny minerals from Utah.”   Around that time, Haynes encountered Dr. Peter Burns from University of Notre Dame, under whom Olds had studied when earning his PhD. He sent samples of the questionable material to Dr. Burns and PhD students to study. Dr. Olds, now a post-doctorate researcher at the University of Washington and his associates produced a successful and convincing analysis. Then Tony Kampf and several other mineralogists provided further input. The result was the submission of an abstract to the IMA for approval  of a new species, to be named leesite. The approval came in 2016.

IMA rules stipulate that approval of a new species becomes official only after the authors of the abstract seeking that approval have published a synopsis. That happened in January, 2018, when the American Mineralogist published a synopsis of leesite by Olds, Kampf, et al. Patrick Haynes believes that only 130 samples of leesite are known to exist.  All of them, were collected at the Jomac Mine, which was reclaimed in 1992, and leesite has been reported from no other locality on earth.

Thursday, February 8, 2018

Alfredo Petrov and an Opal Sulfur Dilemma


Something is different  in Tucson this year. Alfredo Petrov and his inventory of  mostly unusual specimens with precise handwritten labels are  nowhere to be found at the Inn Suites. Nor will he be doing the big show. Instead,  he is among a small group of  wholesale and retail dealers with interesting minerals in the JTI tent at La Fuente de Piedras, 1535 North Oracle.

Here as at the Inn Suites, Alfredo holds forth about minerals with  a diverse stream of connoisseurs, cognoscenti, and the simply curious. More often than not, the topic relates to specimens he is selling. It seemed odd when he picked up from amongst those specimens a small cabinet specimen of native sulfur crystals. Their locality was the El Desierto Mine in southwestern Bolivia. These crystals seemed at first an unlikely pick for Alfredo, a dealer of minerals that are less common.  Nearby, a Jewel Tunnel Imports table was completely covered with similar pieces.

Alfredo acknowledged that that it was the bright yellow color of these and all native sulfur crystals that attracted most collectors. Except for certain uranium bearing minerals, not many easily acquired species  can compete with them in terms of brilliance. He recalls when his mentor, the late mineralogical icon Rock Currier instructed him: "Alfredo, I'm going to teach you the three secrets to success at selling minerals. They are #1 color; #2 color; #3 color." Interestingly, Currier was the first  to bring  El Desierto Mine sulfur crystals to the US. He imported about 15 tons of them.  Over the last decade, other dealers have imported another five or so tons. The market for these beautiful crystals is endless.


Alfredo's interest, however, goes beyond the color. He points to the white transparent material atop some of the crystals. It is hyalite opal. Viewed from a distance, its presence makes the crystals  seem less distinct, even less brilliant. Alfredo explains:
"What's important is that the sulfur forms from volcanic fumarole fumes. The sulfur is in the gas, and the crystals grow out of the gas. There is no liquid involved as there is when most minerals form. If the hyalite opal formed volcanic gases, where could the silica be in that gas? Opal is derived from quartz, which doesn't evaporate, so you don't get siliceous gas. 
He continues:
"The melting point of sulfur is 108°C. The presence of the hyalite proves that the temperature of opal deposition. was 108°C or less. If the opal had ever reached that temperature, the sulfur crystals would have been melted. "
 Alfredo then points to a larger specimen where a small amount of the sulfur is black in color. He notes that analysis has shown the black material to be covellite, a copper sulfide. This occurrence raises a similar question. The type locality for covellite is Mount Vesuvius, which demonstrates its potential for volcanic origin.

Metallic sulfides formed  as volcanic sublimates are rare albeit explainable. But how does one explain the  presence of silica in any any kind of volcanic sublimate? Despite his legendary knowledge of minerals, Alfredo does not have a sure answer.

"There is a well-known theory among volcanologist," he notes, "that silica is trasported by HF (hydrofluoric acid), a very, very, very nasty gas, which transports silicon as SiF4 (silicon tetrafluoride)."

Alfredo spends considerable time field collecting in volcanic regions, especially in Japan. And then:

"If this is true, then spending much time breathing around  volcanic fumaroles would be a very unhealthy experience, and I'm going to die a nasty death."

Let's hope it isn't true, and there's a different chemical mechanism we don't know about yet.


 I



Sunday, November 26, 2017

A Wonderful Display of Japanese Mineral Specimens




The mineral room at Japan's National Museum of Nature and Science at Ueno Park in Tokyo offers a different kind of experience than most other museums where minerals are on display.

Its focus is less about "eye candy" and more about   hundreds of  different mineral species showcased by  a thoughtfully designed lighting system. Most are medium sized cabinet specimens supported by brackets.
    
To foreign visitors unaware of what to expect, the exhibit should appear to be a very diverse collection of species. Thankfully, the labels name them in English as well as Japanese. Other pertinent information, including localities, are in Japanese. 

The collection leans heavily toward uncommon minerals and rarities. Mineral names like ohotskite, yoshimuraite, and tsugaruite bespeak the emphasis on species first identified in Japan. Mindat reveals many are found exclusively in Japan. A museum website  in English shows a catalog for an enormous inventory naming species, catalog number, country, and prefecture. It makes clear that the collection is all about the minerals of Japan. 

 One exclusively Japanese species that has gained stature among collectors  is henmilite.  This gorgeous  deep blue colored borate typically occurs in association with calcite and olshanskyite. It is found nowhere else in the world except the Fuka Mine on Honshu Island. The specimen pictured at left is on display immediately outside the mineral room. It  is world-class if not best of species. The close-up shot at right of a tiny piece illustrates henmilite's aesthetic appeal at closer range.   

Overall, the minerals here are not likely to generate as many "ooh's and ahh's"  as do selections at most other serious mineral exhibits around the world; however, viewers with a special interest in Japanese minerals or rare species are likely to be enthralled. Because many such specimens fall into the category of microminerals or are known to exist in very small quantities, a microscope is often necessary to properly view them. Even with deliberate lighting and occasional use of of arrow stickers pointing to their presence in larger rocks, to truly appreciate them visually can be a stretch if not impossible.                  

Because  such specimens are likely to interest but a small segment of  the population, some may question the purpose of including them for the masses to see in such a major public exhibit. Others, especially those interested in viewing the minerals of a country at its national museum, are likely to have special appreciation for the decision to acknowledge and make such an effort to display so many.  

Thursday, October 12, 2017

Amazing Hematite Find in Baltimore County, Maryland

This 8 x 7 x 3.5 inch specimen 9 poun specimenfeaturing bladed hematite crystals on chlorite schist from Baltimore County could well be the most intriguing Maryland-collected mineral to show up in the last decade. During the recent Gemcutters Guild of Baltimore's Atlantic Coast Gem, Mineral, and Jewelry show at the Howard County Fairgrounds, it was on display for all to see in a cabinet of about a dozen other specimens that Gemcutters long time member and show-organizer Bernie Emery had self-collected. Notwithstanding, it seemed that but a few of the numerous local mineral aficionados who were there manged to combine the levels of  detailed attention and specialized knowledge to realize the significance of what they were seeing.

It's a find that's almost impossible to believe as well as to refute. Though hematite is the world's primary ore for producing iron and is common in Maryland, it accounted for very little of  the production that thrived here into the early part of the last century. Instead, goethite, magnetite, and siderite  were the principal ores, except on the Coastal Plain where "bog ore" was prevalent.  Maryland's hematite occurs in either rough grainy dark red/black masses or as specular hematite, known also as"specularite." The latter appears as silvery flakes and/or microscopic tabular crystals. Hematite with the appearance of Bernie's recent find is all but unknown in Maryland. After 10 years writing and photographing Maryland-collected minerals and assuming sole responsibility for the Maryland Minerals website, this writer has never seen or heard of another such specimen.

The specific Baltimore County location where Bernie Emery found the specimen is especially curious. He surface-collected it at one of several pits worked for iron over a century ago. They all are a short distance from the NCR Trail near the former Blue Mount Station in Baltimore County. Records show the  ore source to have been exclusively magnetite.  Various publications that describe the mineralogy of the immediate area as well as its specific iron pits and prospects name a variety of minerals. They include tourmaline, apatite, garnet, actinolite, and hornblende. There is no mention of hematite or any other species worthy of mining. The country rock varies from serpentinite to chlorite schist.

Few if any collectors in the region could be more deserving of such a find than Bernie. Over more than three decades, he has been one of its most prolific and best known field collectors. Along with his wife Lynne, he has continuously held major leadership roles at all three of the area's pertinent organizations: Baltimore Mineral Society;  Chesapeake Gem and Mineral Society; and  Gemcutters Guild of Baltimore. His renown is enhanced by a penchant for collecting large sized specimens. That practice has prompted many friends and colleagues to refer to such specimens as "Bernie sized." Retirement from his day job several years ago has brought additional time to enjoy his hobbies. More than ever now, he has taken to perusing old maps and literature in a quest to find new spots to look for rocks.  He likes geological maps that hint where mineralization could be likely, and very old ones that mark the locations of   former and usually long forgotten (and all too often reclaimed or built over) mines and quarries.

After explaining the nature of his research, Bernie explains how the find happened:
I was walking up what appeared to be a  dump pile leading to a small pit that was full of water. On the pile, all the rocks were a rough chlorite schist  with a few small garnets. I noticed this one boulder that was covered with dirt and was curious what was inside it. I tapped off a piece with my hammer. The chlorite schist  was highly metamorphosed  with microscopic magnetitie crystals. I dismissed it and kept walking. 
Except for curiosity, Bernie offered no explanation as to why he returned a few seconds later.
I went back, turned it over. and saw pods filled with the dirt  this boulder had been in for 150 years. The pods appeared to be some other kind of material. There were no blade shapes  (as would suggest hematite). I used a stick to remove some of the dirt and got the impression it was some kind of honeycomb quartz or chalcedony. Further cleaning, I realized they were actually hematite blades that were completely rusted. I showed it to Bob Eberle who offered to clean it further. 
Eberle whose prowess at field collecting is legendary,  had  access to a glass head sand blaster. He took the specimen home and cleaned it up to reveal what he refrred to as "this amazing surprise."

And the question remains. How could such a specimen be here?  According to Bernie:
There's no way of knowing, but my guess is that it came from deep down in the pit and that it was put on a cart or a wagon and fell off. There's no way anyone would have left it there. 
He has since returned to the site and searched extensively.  No trace of hematite or any other specimen of interest  turned up.  Bernie's theory makes sense, but it is unlikely that anyone will ever  know for sure.

Tuesday, August 29, 2017

Viewing Minerals at Yale University: 2015 and 2017

A lot has changed. At left are pictured  cabinets with most of the minerals on public display at Yale University prior to the  October, 2016, Grand Opening of the new David Friend Mineral Hall at Yale's Peabody Museum of Natural History at 170 Whitney Avenue in New Haven.

Despite being a rock rather than a mineral specimen or gem, the orgasmic sandstone concretion at right from Fontainbleu France is but one example of what is in the Museum's new home for visually and aesthetically over the top specimens. Quite appropriately, it is from the collection of David Friend,  mineral aficionado  and 1965 Yale graduate (BS in Engineering).  Mr. Friend's leadership, guidance, and philanthropy paved the way to establish the museum's grand new addition.

 Many of the largest and most eye-catching specimens here are  on loan from prominent collectors such as Dr. Rob Lavinsky, Jim and Gail Spann, or Gene and Rosalind Meiran.  Among them are pieces that could be the best of  their genre known to exist. It is only natural that those who visit will be interested in viewing such  "eye candy,"

The David Friend Hall is on the 3rd floor of the Peabody Museum in a renovated space that an auditorium once filled. To the right of the hallway leading to it are the foot by 18 inches pink calcite twin from Scott City Missouri  at left amd the.300 pound baryte specimen pictured directly beneath it from nearby Branchville, Connecticut. Yale owns both of these specimens.



In a room to the left of this hallway is the Treasures of the Mineral World  room.  Most if not all of the rocks and minerals therein along with some jewelry have been selected from Yale's collection of more than 40,000 specimens. The displays are didvided  into categories such as mineral specimens placed according to their nature of origin and locality, minerals that fluoresce, radioactive minerals, some jewelry, and a cabinet with large examples of of well known rocks. Of particular interest is an exhibit of minerals collected in Connecticut.  Almost for sure, it is the "best" Connecticut suite in existence. Quite remarkable is the magnificent sillimanite shown at left. Sillimanite is eponymous with Benjamin Silliman, the Yale Professor who in 1802 began assembling and for more than 50 years curated Yale's  mineral collection.

Regardless of  knowledge about or interest in minerals,  however, upon reaching  the David Friend Hall of Minerals, visitors are in for an experience that should blow their minds.  The theme is world class specimens enhanced by world class lighting. In number, there are more than enough to appreciate, but not so many as to overwhelm. Pictured below are just a few images of what is there.

                               Malachite, Azurite                                    
Liufengshan, Guichi District  
Anhui Province, China

 Stibnite
Wuning Mne
Jiangxi Province, China


Fluorite, 
Yaoganxian Mine
Hunan Province, China



Fluorite, Baryte
La Cabana
Asturias, Spain
   
                                                                                                                            
Aragonite
Yunnan Province
China