Wednesday, March 7, 2018

Leesite: Another New Species Discovered by Patrick Haynes


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.