Type species from Bisbee, Arizona
To date, more than 325 distinct mineral species have been confirmed as occurring at Bisbee. Of these, eight were first described as new species using specimens from this prolific locality, thus Bisbee is the type locality, or as in the case of kiddcreekite, the co-type locality. In the order of description, these are:
SPANGOLITE – 1890
PARAMELACONITE – 1891
SHATTUCKITE – 1915
BISBEEITE-? – 1915
CHALCOALUMITE – 1925
GRAEMITE – 1974
HENRYITE – 1984
KIDDCREEKITE - 1986
The science aside, each of these species has a story of sorts, as to how it was found and how it generated sufficient curiosity to undertake the rigorous and expensive process of becoming recognized as something new to science. In the case of bisbeeite, there is a tale as to how some believe it to be simply a mixture of other minerals and not truly a valid species, something I still question. This short paper is an effort to go before the science and briefly summarize what is known about each of the individual species as well as to follow with what has been learned about the species subsequently, where it pertains to Bisbee. Some of what is written is based on stories heard long ago and some on informed speculation. Nevertheless, these are worth recording as the “Great Thief”- time will take for its own, all record of what was said or believed with the inevitable passing of those who have heard or seen.
In truth, the exact locality for the type specimen has long been something of a mystery, but is believed by those who have studied the issue to be Bisbee (Palache & Merwin, 1909, Anthony, et al. 2003). The confusion as to the exact source of the type specimen begins with the initial work, as recounted by Penfield (1890) in his description of the species, the location was uncertain as he wrote: “During the summer of 1889, while visiting Mr. Norman Spang of Etna, Allegany County, Pa., my attention was called by him to a very beautiful crystallized specimen of an unknown mineral which he had obtained from a man living near Tombstone, Arizona. The original owner had a small collection of minerals which he had gathered together within a radius of about two hundred miles but he had no idea of just where he had found the specimen, though he thought it was from the Globe District. Mr. Spang had forgotten the name of the man from whom he had secured it, so that until other specimens are found uncertainty must exist about the exact locality and mode of occurrence. On expressing a desire to investigate the
mineral, Mr. Spang very generously lent me the specimen and has since presented me with it, and it is now deposited in the collection of Professor Geo. J. Bush, at New Haven. A preliminary blowpipe examination showed that the mineral was undoubtedly a new species and essentially a hydrated sulfate and chloride of copper, and I take pleasure in not only expressing at this time my thanks to Mr. Spang for his kindness but also in naming the mineral, which as will be shown, is of unusual interest, Spangolite, after him.
The original specimen, was about the size of a small hen’s egg and consisted of a rounded mass of impure cuprite which was
Figure 2: Crystal drawings of spangolite by Penfield (1890)
mostly covered with hexagonal crystals of spangolite associated with a few crystals of azurite and some slender prismatic crystals of a copper mineral containing chlorine, probably atacamite.”
Figure 1: Holotype specimen of spangolite on cuprite with connellite. 7 cm.
Yale University collection
Lastly, in his description of Spangolite, Penfield added: “Before closing the author desires to express the hope that some one [sic] living in the neighborhood of Tombstone, Arizona will take an interest in examining both the collections and the ores of that region so as to secure, if possible, an abundant supply of this mineral.”
Figure 3: Spangolite with cuprite from Bisbee in much the same crystal habit as the type specimen, 11 cm. Montana Tech. collection.
Palache and Merwin in their 1909 paper on connellite and chalcophyllite noted
“Considerable\ interest attaches to the occurrence of these minerals [connellite, chalcophyllite] at Bisbee, because of their association elsewhere with spangolite. It will be well to recall that the type specimen of spangolite came from an unknown locality in southern Arizona. With it were minute blue prismatic crystals not determined by Penfield, but suggesting connellite. While spangolite has not yet been found at Bisbee, it now seems highly probable that the original specimen came from there, and that it may be rediscovered if carefully sought for.”
Figure 4: Spangolite as crystals to 1. 7 cm. Harvard University collection
Figure 5: Spangolite crystals to 1 cm. on malachite with goethite and cuprite at the 1997 Munich Show, Houston Museum of Natural History collection
Figure 6: Spangolite with atacamite on cuprite, view – 3 cm.
However, Ford (1914) studied and reported on a specimen of spangolite with cuprite from the Czar Mine at Bisbee and a second sample from the Grand Central Mine at Eureka, Utah. In responding to a suggested Utah source for the original type specimen wrote that “The original specimen, however, is quite distinct in character from either of the occurrences described above.” In short, he could not ascribe a Bisbee location to the original type specimen based on an examination of the new material he had in hand.
In 1949, Clifford Frondel of Harvard published a paper on the Crystallography of Spangolite, in which he stated that “The locality was given only as within a radius of 200 miles of Tombstone, Arizona and has not since been more clearly established.” He rendered no opinion as to the locality of the type material. While Frondel did not examine the type specimen for this study, he studied a specimen of spangolite from the Czar Mine and did contrast the apparent physical crystal habit with that of the type specimen and material from other localities, as there were striking differences.
Anthony and others (1995) say the type material “…strongly resembles Bisbee material.” Later, in the Handbook of Mineralogy, volume 3, (2003) Anthony, Bideaux, Bladh and Nichols are decidedly more specific wherein they write “…almost certainly from Bisbee…” I agree that Bisbee is indeed the type locality for this elusively rare mineral species.
Over the last half century, I have examined a good number of Bisbee spangolite specimens including the very few outstanding examples as well as the type specimen at Yale and the small amounts of type material held by the USMNH and the British Museum of Natural History. A variety of crystal habits can be found among the spangolite specimens confirmed from Bisbee, including that which is found on the type piece.
Perhaps most importantly, I have field collected spangolite at several Bisbee sites, including in the original Copper Queen Mine, and thus have had the unique opportunity to fully explore the depositional environment and the full range of associated minerals as well as their appearance.
With this basis and the fact that the character and appearance of the cuprite and associated species on the type specimen are so distinctive, leave absolutely no doubt in my mind that Bisbee is the type locality for spangolite. Possibly half-a-dozen extraordinary spangolite specimens have been preserved from Bisbee since it was first described. These are all very similar to the type specimen and, like the type piece, far superior to specimens from any of the several other spangolite localities since identified.
Dr. A. E. Foote, the noted Philadelphia mineral dealer, visited Bisbee in 1890 to purchase mineral specimens for his business. Among the minerals he purchased were two, well crystalized specimens of an unknown black species. Local lore has it that these specimens were on a shelf in the Copper Queen assay office when Foote was shown them (M. J. Cunningham, personal communication, 1954). In any event, upon his return to the East, he sold both specimens to Clarence Bement for the-then princely sum of fifty dollars apiece (Frondel, 1941).
In addition to the striking black crystals, one specimen was partially covered with deep blue acicular crystals of an undetermined mineral and both pieces had a partial coating of a slivery- green mineral that was also unidentified. Bement then had the well know mineralogist George A. Koenig investigate the unusual specimens.
Figure 7: Koenig’s illustration of paramelaconite (A) and connellite (B) on goethite (C & D) on cuprite (E) with copper (F), (1891). See figure 8 below.
Figure 8: Co-type specimen of paramelaconite with connellite on goethite, view – 4 cm. American Museum of Natural History collectio
Koenig spent a good deal of time studying the specimens and determined that the large black crystals represented a new, distinct species and proposed the name paramelaconite, in allusion to its similarity to “melaconite” or tenorite. He determined that the blue crystals were a “chloro-oxyhydrate” of copper, which he also believed to be a new mineral as well and for which he proposed the name “footeite, inasmuch as the species was determined on identical material provided by Dr. Foote. As for the silvery-green material, it proved to be malachite.
True science always challenges and over time the paramelaconite specimens were reviewed and retested. While minor modifications were made to the composition and crystallography, it has stood as a distinct species. On the other hand, “footeite” was found to actually be connellite (Ford & Bradley, 1915). Connellite is a complex species, one which would confound others in later years (Holden, 1924, McLean & Anthony, 1972).
Figure 9: Co-type specimen of paramelaconite with minor malachite, 10 cm. US Museum of Natural History collection
Interestingly, even though Bisbee was to be mined for 85 more years, no additional specimens of paramelaconite were ever recovered. Massive cuprite-type environments very suggestive of that which produced the original paramelaconite were frequently mined, and while other rare species were found, paramelaconite was never again recognized. However, connellite, while never abundant, was found in a number of areas throughout the oxidized ores, always with cuprite. In some cases connellite was found as extraordinary specimens, but never in crystals the size and quality of those associated with the paramelaconite specimen. Over the years, several small crystals were removed from the original paramelaconite specimens and provided to universities and museums to serve as reference type specimens. In all there are but six known pieces of Bisbee paramelaconite with only two greater than two cm in size. As an aside, the mine credited as the source of paramelaconite is the Copper Queen and this may well be correct, but operations in the Copper Queen Mine were stopped in 1888 and all mining undertaken through the nearby Czar Mine. Indeed, the Czar had been the principle ore and specimen producing mine from mid-1885. The same orebodies were being mined with the majority of ores hoisted through the more efficient, vertical Czar Shaft instead of the small and inclined Copper Queen Shaft. The assay office where Foote may have acquired the specimens was built in 1888 as well, along with the construction of the new smelter next to the Czar Mine. As all mines at Bisbee owned by the Copper Queen Consolidated Mining Company were generally referred to as the “Copper Queen,” there is a very real chance for confusion. In any event, I have personally examined the two larger type specimens and found that the matrix on the piece in the American Museum is very characteristic of Czar Mine material and am of the opinion that the Czar was most probable the source of these fine specimens. Over the last 120 + years, paramelaconite has remained an exceedingly rare mineral, with no additional material found at Bisbee, but a few confirmed new localities elsewhere which have produced minor amounts. The Bisbee type specimens are far and away superior to anything found these other localities.
The year 1913 was an exciting one at the Shattuck Mine. A large and magnificent cave was struck on the 300 level and a crosscut on the 200 level being driven to intercept this cave cut through a narrow fault zone with a silica breccia in the footwall hosting modest amounts of an unusual pale-blue mineral. Phillip D. Wilson, Chief Geologist for the Shattuck and Arizona Copper Company, sent samples of the strange material to the laboratories of the U. S. Geological Survey in Washington, D. C. for identification (Schaller, 1919). It was found to contain two minerals new to science, one of which Schaller named shattuckite for the Shattuck Mine (Schaller, 1915). The other, he would call bisbeeite.
In the very brief note published on shattuckite, Schaller (1915) wrote that “Shattuckite forms pseudomorphs after malachite and also occurs as small spherulites.” It does appear that the vastmajority, if not all, of shattuckite from the type locality has indeed formed as a replacement of malachite. On occasion, the relic form of the earlier malachite can be quite apparent.
Here too, the species was challenged when in 1918, Zambonini suggested that shattuckite and planchéite were the same species. Schaller (1919) quickly responded with optical data that supported his position that that shattuckite and planchéite were two separate and distinct species.
Over the next 50 or so years Schaller and several others would publish studies on shattuckite, ultimately using material from Ajo, Arizona to fully establish the chemical formula, as the material from Bisbee was found to be too impure (Vlisidis & Schaller, 1967).
Bisbee shattuckite is quite different in appearance from shattuckite from Ajo or any locality for that matter. Unfortunately, much Ajo material is sold as having come from Bisbee. While shattuckite from Bisbee is not rare like most of the other minerals first found here, it is not truly common either. I doubt that there are more than a couple of hundred true Bisbee type-locality shattuckite specimens in collections world-wide.
In the early 1970s a few dozens of specimens were recovered when the Shattuck Mine was reopened for precious metal exploration efforts. Additionally, shattuckite has been recognized at two other spots in Bisbee, but the quantities are so modest as to render these occurrences more as curiosities than sources of specimens.
For the most part, true Bisbee shattuckite is pale- blue to gray-blue and porous if not almost boxwork-like, not surprising inasmuch as it is usually a replacement of malachite. The more attractive material consists of clusters of very small spherical sprays of acicular crystals that are typically darker in color than the porous shattuckite matrix (Figure 11). Bisbee shattuckite never gives the impression that it had formed in a vein bounded by iron tinted quartz like the Ajo material. All of the quartz associated with the type locality material is as angular breccia fragments or as tiny colorless crystals, not open-space filling.
Figure 10: Shattuckite and bisbeeite with malachite from 69 prospect, 200 level Shattuck Mine, the type locality for shattuckite and bisbeeite, 20 cm. Collected in 1913, Shattuck collection, Bisbee Mining and Historical Museum specimen.
Figure 11: Shattuckite with minor bisbeeite as replacements of, and with malachite, 8 cm, 200 level, Shattuck Mine, (type locality), Graeme collection.
Figure 12: Shattuckite as a replacements of malachite, with the relic features of malachite clearly apparent, 11 cm, 200 level, Shattuck Mine, (type locality), Graeme collection.
Figure 13: Typical Bisbee shattuckite with malachite, 13 cm, 200 level, Shattuck Mine, (type locality), Graeme collection.
Schaller (1915) proposed the name bisbeeite for the pale-blue to near-white copper silicate found with shattuckite as replacements of shattuckite pseudomorphs after malachite. He noted that the composition was identical to dioptase and that bisbeeite had distinctive optical properties. Subsequently, bisbeeite was reported from several other localities, particularly in Africa.
Good science demands constant review and challenges and much like the other species first found at Bisbee, bisbeeite was studied. Several studies indicated that bisbeeite was not a valid species, but rather a variety of planchéite (Schoep, 1930) or chrysocolla (Billiet, 1942) In 1962, Laurent & Pierrot studied type material as well as material from an African locality, defined the optical properties and chemistry of bisbeeite arriving at the conclusion that it was indeed a valid species. Later, Oosterwyck-Gastuche (1967) studied what was said to be bisbeeite from an African source and she determined that it was a mixture of chrysocolla and planchéite.
Bisbeeite from the type locality was not used nonetheless, the species was discredited in 1977. Bisbeeite from the type locality is not particularly rare and is present on many of the shattuckite specimens. The difficulty is in acquiring reasonably pure material for study, as the shattuckite it replaced was often impure to start with.
During the early 1990s Sid Williams, Richard Bideaux and myself agreed that discrediting a species based on a study that did not involve type material seemed ill advised. With Sid leading the way, we undertook a modest effort to see what might be learned from a new look at bisbeeite using Sid’s equipment. I provided material from the type locality that consisted of shattuckite with what I supposed to be bisbeeite.Sid spent hours selecting small pieces for
Figure 14: Bisbeeite (type specimen) replacing shattuckite pseudomorphs after malachite, 9 cm., Shattuck Mine, (type locality), USMNH collection.
Figure 15: Bisbeeite replacing shattuckite pseudomorphs after malachite, 6 cm., 69 prospect, 200 level, Shattuck Mine, (type locality), Graeme collection.
x-ray, ultimately running five samples which gave a decidedly strong pattern and satisfied him that, based on the x-ray work at least, bisbeeite was viable as a distinct species. However, efforts to replicate the reported chemistry were frustrated by impure material. The project got shelved for another day when Michael Fleischer dropped bisbeeite completely from his incredibly fine and comprehensive “Glossary of Mineral Species,” something he had promised Dick Bideaux he would not do absent further work to disprove the species. Bisbeeite may still be a valid species, but much work will be required to make the case. Because of the inherent problem of impurities in the Bisbee material, it be some time before the detection equipment evolves to the point that true type material can be examined in a manner such that the question of the validity of bisbeeite as a species can be answered. Meanwhile, the science that has relegated it to the realm of discredited species must be accepted, challenged with additional testing, but nonetheless accepted for the moment. Material identified as bisbeeite has been found in several places around the World, but is never truly common at any of these localities.
In 1925, Esper Larsen and Helen Vassar, both of Harvard University, published a paper in The American Mineralogist titled “Chalcoalumite, a new mineral from Bisbee, Arizona.” In this paper, they recount how they came to describe this new mineral species as follows: “Among a number of specimens from Bisbee, Arizona, sent to the authors for identification by Mr. English of Wards Natural Science Establishment, three contained a crust of a delicate blue-green material that proved to be homogeneous on microscopic examination and had optical properties that did not agree with those of any known mineral. Mr. English and Wards Natural Science Establishment generously presented us with the specimen that seemed most suitable for further study…”
Figure 16: Chalcoalumite on and replacing azurite and malachite, 12 cm. Holbrook Extension, Lavender Pit Mine, Graeme collection
Commenting on the probable abundance of chalcoalumite, Larsen and Vassar continued with “We have since identified the mineral in two other specimens from Ward’s collections; and Professor Palache has identified it on two specimens in the collection of Mr. Vaux of Philadelphia. Several specimens in the collection at Harvard University, called to our attention by Professor Palache, are with little doubt an alteration product of chalcoalumite. No doubt the mineral will be found in other collections. The specimens we have identified have been labelled either chrysocolla or allophane. … From the number of specimens that have been found, the abundance of the mineral on the specimens, and the fact that it seems to have completely coated the limonite surfaces in the cavities, it is probable the chalcoalumite occurred in considerable quantity.”
They were correct in suggesting that substantial chalcoalumite had been deposited, as there are many hundreds of specimens of chalcoalumite known from Bisbee. However, truly fine and undamaged specimens are uncommon, if not down-right rare. The scarcity of fine chalcoalumite specimens has much to do with its typical mode of occurrence as a thin (1-7 mm), somewhat friable replacement crust on malachite and/or azurite. Chalcoalumite almost always formed at the expense of the underlying copper carbonate, a result of moderately-low pH, and corrosive, aluminum-rich fluids coming into contact with the earlier malachite and/or azurite. Rarely was chalcoalumite well attached to the copper carbonates and tended to readily flake off at the slightest of bumps. Collecting chalcoalumite specimens from blasted ores was challenging, as the force of the blast so often dislodged some, if not most of the crust and too, its occurrence in association with iron-rich clays often left reddish marks that could never be totally cleaned.
In any event, chalcoalumite had been collected at Bisbee as early as the mid-1890s, but always thought to be chrysocolla or allophane, an understandable confusion. In our collection we have a specimen of chalcoalumite labeled “chrysocolla” with a glued-on A. E. Foote label from this period (Figure 17). Surely, many more exist.
Inasmuch as most all chalcoalumite occurred as a replacement of malachite and/or azurite, cast pseudomorphs of azurite crystals are common, as is the obvious replacement of malachite or botryoidal azurite by this mineral. Chalcoalumite was invariably the last mineral deposited in the limited and isolated environment where it formed. No other later minerals have ever been observed on chalcoalumite on specimens from Bisbee. This is a useful feature when determining if the material is indeed chalcoalumite, as gibbsite, which can resemble it, often has other, later mineral species present.
While Larsen and Vassar did not indicate the mine from which the type material came, the Holbrook Mine between the 200 and 300 levels and close to the Sacramento Stock Complex is most assuredly the source for the type material. No other mine in the district has produced any chalcoalumite, except the Holbrook Extension of the Lavender Pit Mine, which re-mined the same area.
Figure 17: Two views of a chalcoalumite on goethite, malachite and azurite with an A. E. Foote label of “chrysocolla,” C-1895, 7 cm., Graeme collection
During late 1969 into early 1974, the Holbrook Extension of the Lavender Pit Mine exploited the remaining copper ores from the area adjacent to the Sacramento Stock Complex. While mining by underground methods had occurred from the early 1890s through mid-1944, the large masses of supergene clays in the area created difficult, if not treacherous conditions, thus some mineral was left in place. These clays did little to impede the large electric shovels in the 1970s, as they could easily slice right through them to the ore. At this time, modest amounts of chalcoalumite were found close to the stock as delicate crust on malachite and/or azurite. Much of this material was salvaged by the mining company as mineral specimens and it was my job to collect these specimens as they were found. In reviewing the company files, it was determined that chalcoalumite was found in an area that corresponded to what was once between the 200 level and 300 level of the Holbrook Mine.
Figure 18: Clusters of tiny chalcoalumite crystals on goethite. View - 1 cm. Holbrook Extension, Lavender Pit Mine, Graeme collection
In addition to the aforementioned form of chalcoalumite, there was a limited zone of incredibly hard goethite in this same area. Voids in this hard goethite occasionally hosted very modest amounts of chalcoalumite as drusy crust on malachite, often malachite pseudomorphs after azurite or clusters of acicular malachite crystals, sometimes completely replacing the malachite. Rarely, tiny clusters of chalcoalumite crystals unassociated with malachite were scattered about in these small vugs (Figure 18). Sid Williams and Ba Saw Khin (1971) used a specimen of this material loaned by Bisbee collector Al Voirin, to fully define the crystallography of chalcoalumite, thus completing the work of the original describers nearly 50 years later.
As noted by Larsen and Vassar (1925), some examples of gibbsite and other species from Bisbee can easily be confused for chalcoalumite, as their appearance and association is quite similar, but all have a decidedly lighter color. Some of these specimens are believed to be replacements of chalcoalumite by gibbsite and are not at all uncommon. Others are a simple late- stage overgrowth of similar appearing species such as nordstrandite, halloysite, allophane or alunite.
On a world-wide basis, chalcoalumite has proven to be a widely distributed mineral occurring in small amounts in a number of oxidized copper deposits.
Figure 19: Nordstrandite (a gibbsite polymorph) as a partial overgrowth on azurite with malachite 17 cm. Holbrook Mine. Graeme collection.
Just as many of the above species sat in collections for some time before determinations were made, it was more than a dozen years from the time I collected what would became the graemite type specimen and the work completed to confirm it was indeed a mineral new to science. During the summer maintenance shutdown of July 1959, I went into the Cole Mine to look for minerals, as I had been told of the occurrence of unusual species in 202 stope on the 1200 level.
As the Cole was somewhat remote, unauthorized access was not too difficult in the late afternoon and the climb down 1,200 feet of the manway was quick and easy. Coming back up was to be a very different story, however. In any event, the long walk to 202 stope seemed to go by quickly as well, with much to see along the way, as I had only ventured into the Cole once before some six years earlier, only to be discovered by a miner who quickly saw me out and into the arms of the Chief Watchmen.
This time, I was far more cautious and arrived at my destination with no problem. Unfortunately for me, the stope had been well cleaned of broken muck, something I would later learn was the practice before summer shutdown, and nothing was to be found. There were however, three loaded mine cars on the level nearby that contained oxide ores from this stope. Digging through the tops of the loaded cars yielded little, but a few of the mud-covered rocks looked interesting and I wrapped them in newspaper to them out. Now, the long climb out and a several mile walk home in the dark.
After cleaning the specimens the next day, one sample was decidedly different from the others in that it had associated minerals I could not identify. It consisted of a spongy mass of malachite with two to four millimeter cuprite crystals and a two centimeter blue-green crystal prominent on one side. Several small, but sharp, electric-blue crystals also protruded from the malachite nearby.
Over the course of the next ten years, many collectors and geologist looked at the piece and generally concurred with my supposition that the unusual-looking minerals were chalcophyllite and connellite, just exceptionally fine examples of both, yet something wasn’t quite right in my mind.
Then in 1973, Phelps Dodge assigned me to work with mineralogist Dr. Phil Matter in a district- wide sampling program for alteration mapping. After a few weeks of working with Phil, I showed him the specimen and told him of my doubts about my original identification. He asked to take it to the Douglas lab of PD and show it to my friend, mineralogist Sid Williams.
A few days later, Phil informed me that Sid had determined the blue crystals to be teineite, but the test on the blue-green material did not match any know mineral, but that he would continue working on the identification. As time permitted, Sid continued to study the specimen including a detailed chemical analysis. He was convinced that this was a new species and advanced with the necessary descriptive work with assistance from Phil.
A few weeks later, Sid received samples from a Phelps Dodge field geologist for identification. The samples contained tiny amounts of teineite and the new material he was investigating for me in voids in chalcocite. A small prospect in the Dome Rock Mountains of what is now La Paz County, Arizona was the source. In any event, as the work on the Bisbee material was well advanced and it was far more abundant thus, it was selected as the type material to be used in describing the mineral which was named graemite by Sid and Phil. The official publication of graemite as a new species was printed in the Mineralogical Record in the January/February issue in 1975 (Williams and Matter, 1975).
To this point, only three graemite specimens are known from Bisbee and but one from the type locality in the Cole Mine. While the fine specimen from the Shattuck Mine is quite similar to the type piece, the other known Bisbee example is different in that it is in tiny amounts with teineite on massive cuprite. A similar assemblage, but distinctly different in appearance.
Since the type material was described, graemite has been identified in small amounts at several other localities. However, the type specimen and one other Bisbee piece are far and away much better specimens than any found elsewhere.
Figure 20: A view of the Cole Mine area in 1965, Graeme Larkin collection.
Figure 21: A view of the ore pocket on the 1200 level of the Cole Mine in 1965, Graeme Larkin collection.
Figure 22: A two cm. graemite pseudomorph after teineite with cuprite and teineite on malachite (holotype specimen), 202 stope, 1200 level, Cole Mine, Graeme collection
Figure 23: Graemite as a 3.7 cm. pseudomorph after teineite with cuprite and later teineite, Shattuck Mine, Arizona Sonora Desert Museum collection.
The evolution in mineral detection and identification equipment has allowed for the definitive determination of very small amounts of material, something impossible even in the recent past. It was this type of equipment that allowed for the discovery of henryite and, later, kiddcreekite.
The incredibly large and rich Campbell Orebody was discovered in 1929 and mined for much of the next 30 years. This pipelike sulfide mass extended from above the 1600 level almost to the 2566 level. Its important gold and silver values were long recognized and played a significant role in the economic viability of Bisbee during the difficult years of the depression when gold and silver prices were dramatically increased.
In the late 1970s, precious metal prices had risen substantially over a few years and Phelps Dodge decided to investigate what opportunities for gold and silver mining might exist in several previously mined areas, particularly in the low- grade massive sulfide shell that surrounded the now-exhausted Campbell Orebody. A great deal of underground diamond drilling and sampling, including bulk sampling, was undertaken by Phelps Dodge. During this effort, numerous samples were submitted to the PD geological laboratory in Douglas for detailed study with the hope of better understanding the occurrence of gold and silver.
A complex, intergrown mineralogy was observed in many of the samples, which upon close examination, showed that very minor amounts of a number of gold, silver, tin, tungsten, vanadium, tellurium, bismuth and arsenic bearing minerals were present. Sid Williams and Steve Eady, the geologist in charge of the project, provided a number of samples to Alan Criddle and Chris Stanley of the Department of Mineralogy at the British Museum for additional study. In all, several hundred samples were studied in great detail to unravel the complexity of this heretofore unrecognized mineralogical event (Alan Criddle, personal communication, 1990; Sid Williams, Personal communication, 1990).
Among the many diamond drill core samples studied, Criddle and Stanley noted a few grains in a polished section that defied identification. They were three grains, which ranged in size from 0.1 mm to 0.8 mm and were associated with hessite, petzite, sylvanite, altaite, rickardite and pyrite. Substantial work ultimately demonstrated that this copper, silver tellurium mix was a new mineral species.
Figure 24: A cross section of the Campbell orebody looking more-or-less north, after Hogue & Wilson, 1950, Graeme, 1993.
Figure 25: A typical example of the complex aggregate of gangue, sulfide and accessory minerals from the Campbell Orebody. While there are at least six distinct species in this sample, henryite is not believed to be present. Size: 6 cm. Graeme collection
Criddle and Stanley described the single specimen as follows (“Henryite was found in a polished section [E.736; BM 1982, 1] of drill-core from the Campbell orebody, Bisbee, Arizona, U.S.A. The three grains found are irregularly shaped with curved and straight margins against the hessite and petzite intergrowths which enclose them Hessite also fills straight and curvilinear partings within henryite. The largest grain (1) is about 0.5 mm across …; the medium grain(2), roughly 0.8 mm long by 0.1 mm across; and the smallest (3), a round-cornered angular grain, is about 0.1mm across … They are all anhedral. The enclosing hessite and petzite intergrowth is itself interstitial in subhedral, granular to massive pyrite. A few minute patches of compound grains of rickardite (<10 µm across) associated with discrete grains of sylvanite (also less than 10 µm across) are included in the two larger henryite grains.”
To honor a former colleague, Criddle and Stanley proposed the name henryite for this new mineral. Their suggestion was accepted and the species was named for one Dr. Norman Fordyce McKerron Henry (1909-1983) of St. John's College, Cambridge, England, who was affiliated with the Department of Mineralogy and Petrology at the University of Cambridge. Bisbee - henryite has to be the rarest of all of the species first described from here with but three tiny grains known from the type locality. Extensive and in-depth studies of the complex mineral assemblage in a large number of samples from the Campbell failed to yield any additional henryite. While henryite has since been found in a few other localities world-wide, it remains a very rare mineral.
It was the same detailed mineralogical investigation of the Campbell Orebody sulfides for the source of precious metals that yielded some of the material that ultimately became kiddcreekite. At Bisbee, kiddcreekite was a very minor part of a complex, late-stage mineral assemblage that had been overprinted on the massive pyrite shell of the Campbell Orebody (Graeme, 1993). Bisbee is considered as a co-type locality for this copper, tin, tungsten sulfide mineral (Anthony, et al., 1995).
The descriptive work was undertaken on material from both the Kidd Creek Mine in Timmins, Ontario, Canada and the Campbell Mine at Bisbee (Harris, et al., 1985). As material from the Kidd Creek Mine had been studied prior to the
discovery of the Bisbee material, but not fully described due to a paucity of material, thus it was named for the Kidd Creek Mine.
Much like henryite, kiddcreekite occurred as tiny grains in and associated with broad assemblage of other hypogene minerals. As Harris and others wrote about kiddcreekite grains “All of them occurred in pyrite as discrete anhedral grains, usually less than 50 µm across, as irregular cores to zoned subhedral grains of colusite (<50 µm)… and as compound intergrowths with colusite, tungsten- bearing colusite, stützite and altaite (<120 µm)…” Unlike henryite, a number of kiddcreekite specimens were found, making it far less rare than henryite. All Bisbee kiddcreekite specimens require the use of a microscope and a keen understanding of the mineralogical assemblage to clearly discern the species.
Subsequent to the description of kiddcreekite on Timmins and Bisbee material, this rare mineral was noted in sulfide assemblages at two other localities, but remains a rare species.
The advent of incredibly sophisticated detection equipment will, most assuredly, add more to the list of mineral species at Bisbee, as it already has. Within the many tens of thousands of specimen from Bisbee that adorn collections over the whole of the World, there are undoubtedly unrecognized species, if not species new to science. Close examination of Bisbee specimens always yields surprises. Henryite and kiddcreekite are perfect examples. The final chapter of Bisbee’s mineralogy is yet to be written
Figure 26: A 0.2 mm grain of kiddcreekite rimmed by colusite in quartz with pyrite. The sample is a polished drill core and is one of several dozen examples confirmed during the descriptive study work by Harris, et al. (1984). A gift of Sid Williams, Graeme collection
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