Alunite

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Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?

Below are some preliminary notes I have made about Alunite. This entry and thread has been made as a place holder for information that you will hopefully contribute about Alunite. It should be in no way be thought of as a claim I have staked out to write about this mineral, and in fact is an invitation for someone to step forward and create the article about this mineral. If you are so inclined and have questions about the format that such an article should have, go the The welcome topic at the top of the Best Minerals forum and read what has been posted there. Also take a look at some of the more mature articles that have already been written like Rhodochrosite, Adamite, Millerite etc. You will need also to pick out other images of Alunite that will go into the article.


Alunite
KAl₃(SO₄)₂(OH)₆ Trigonal


Alunite Cabinet specimens?
K2Al6(SO4)4(OH)12
Alunite is a group name as well as a mineral. The group has something more than 15 mineral species, none of them well known to collectors and few of them are ever seen in display collections. It is a wide spread and commonly found in rocks that have been altered by solfataric action. In some places it has formed the action of sulfuric acid on rocks produced by the oxidation of pyrite. At many localities it is so abundant that it is mined for industrial purposes. These commercial localities include but are not limited to Tolfa, near Civita Vecchia, Italy; from altered tuffs near Beregszasz in Hungary; Almeria, Spain; Zaglik in Azerbaijan and Bulla Delah, New South Wales, Australia. At one time the United States Geological Survey was surveying alunite localities as a potential source for potassium. Alunite is a sulfate mineral and found at hundreds if not thousands of localities. For collectors the best locality is the Chinkuahshih Mine in Taiwan which produces crystals as large as 4 cm. The rest of the localities though they may contain thousands of tons of alunite, struggle to produce crystals larger than micromount size. Selected descriptions follow to give you a feel for the mineral. Certainly other interesting localities will be added here as they are brought to my attention. There is just not much of a specimen market for the mineral except for the ones from Taiwan. If there were it would be more common at gem and mineral shows. Other than good crystals specimens from Taiwan you should be able to get best specimen available for less than $50.

Alunite
Italy
Civita Vecchia, Tolfa. “Used as a raw material in the manufacture of alum since early times, alunite has been mined for this purpose or as a source of potash in many countries. The well-known deposits at Tolfa…are veins in trachyte and have been the basis of alum manufacture there since the middle of the fifteenth century.1
1 Dana's System of Mineralogy, Palache, Berman, Frondel, Seventh Edition, Vol. 2, p558.

Alunite
Hungary
Tojak Mts, Szerencs Hills. “Alunite forms in colorless white to pale pink or yellowish tabular and rhombohedral crystals (frequently 1-3 mm, rarely 5-8 mm) in the Szerencs Hills… . It is usually associated with kaolinite, jarosite, and goethite.”1 “As concretions, it is one of the most common sulfate minerals in the upper levels of the bauxite beds at Gánt and Iszkaszentgyörgy, Vértes Mts.; Nyirád and Halimba, Bakony Mts.”1
1 Gheorghe Udubaşa et. al, Minerals of the Carpathians, p. 253.

Alunite
Taiwan, Taipei Co. Jui-Fang Town, Chinkuahshih Mine, Chang-Len level 3. The best alunite specimens from this mine are light tan in color and form crusts of curve chizel shaped blades with crystals up to about two centimeters. They are considered something of a national treasure and Taiwan has even issued a postage stamp in their honor. Miniature to small cabinet specimens of crystal crusts were available from Robert Lavinsky for $300 to $800 each. The Chinkuahshih mine is a gold and copper mine perhaps better known for its enargite (15 cm) crystals and specimens of luzonite and famatinite. It was opened in the early part of the 20th century and closed about 1960. At one time it was the largest gold and copper producer in Asia.
“Well crystallized Alunite in Chinkuahshih was only found in a small area, situated in the upper zone of an Ore Pipe in the Cheng-Len group, where it occurred as thick crusts encrusting breccia fragments. “Most of the crystals are in 1.0-2.0cm range. Some rare sample of complete encrustation of a loose fragment forms a "ball" of Alunite on all sides where collected. Fresh transparent Alunite was rare, mostly it came with ugly dark Goethite coating, but it can be removed by Hydrochloric Acid. Sometimes (rarely) you will find iridescent Goethite coating Alunite clusters, making a rainbow like effect!. The site where most of the World class Alunite specimens was collected was next to one of the largest shaft in Chinkuahshih. The shaft is a part of ore dispense system from 5th Adit down to 6th Adit (now flooded), the site was destroyed by a detonation of Dynamite which created an underground landslide, the whole gallery was collapsed down to 6th Adit! Who made the detonation was unknown, but it certainly was a mistake because it destroyed a lot of Good specimens. No more of this world class specimens was found in the Mine, and the local council block all the entrance that leads to underground due to safety reason.”1
1 [www.geocities.com]
“The old mine of Chinkuahshih is now closed, and no more world class samples of Alunite has been found except some big, unfortunately massive samples found in the dumps. I still have around 10 good specimens cleaned. These specimens are certainly old , as the Cheng-Len ore bed ceased operation at around 1950 and then the Chinkuahshih mine was closed around 1960. Some of these specimens were collected by old miners, and brought to light. and I live nearby. And If I am right, After the closure of the Mine, I think around 1970's, A few collectors saw these samples and went immediately to ask the miner where he found those fancy crystals... and they went down there and collect a few back pack full of specimens. However, one of them must be one of those "collector", who do not wish to do hard work, and decide to use explosive. This was a big mistake!! Alunite mostly occurred as thick fragile crust on the matrix, and when the force of detonation apply on these important crystals...they are all gone! After the "Taiwanese Stamp" was published, they started to think these "Rocks" (In their mine, no Minerals) are some kind of treasure, it makes the situation even harder to get more from old miners. Damage on these specimens are very small, since all of them were covered by thick Goethite, and I just removed the coating afterwards.”1
1 Rob Lavinsky, [www.irocks.com] letter from an unspecified supplier,2003.

Alunite
United States
Arizona, Bisbee. Alunite is a very common mineral at Bisbee but some of the notable occurrences at this locality are “Cole shaft-1200 level, as large, irregular, light green masses. Denn shaft-3100 level, deep green masses encasing euhedral pyrite. Lavender pit, as large, irregular boulders with halloysite. Lowell shaft-1300 level, as attractive white to green banded specimens with kaolinite and halloysite.”1 These entries were taken from Dick Graeme’s fine article on Bisbee.
1 Mineralogical Record, Sept/Oct 1981, p290.

Alunite
Arizona, Ajo, New Cornelia Mine. “Locally abundant in the uppermost portions of the mine…Occurs as dense, porcelaneous, pale greenish yellow veins to 3 inches thick associated with jarosite and iron oxides.”1
1 Mineralogical Record, Vol. 24, 1993, p 293-4.

Alunite
Arizona, Cochise County, Tombstone District. “Alunite is also common as sparkling crystalline druses of clear to greenish crystals.”1They are talking about micro crystals here probably less than 1 mm.
1 Mineralogical Record, Vol. 11, 1980, p 255.

Alunite
California, Mojave, Soledad Mt. (about 3 miles south of Mojave) “There was…a locality just south of Mojave…I mapped it for the USGS in 1980 when we were on the alunite as a source of potassium kick. It had alunite all over the place. I must have collected a couple hundred pounds total, with crystals white to beige to pale lavender, up to about 5 mm, as blades and blocky crystals. Gave them all to Sharon Cisneros when I moved to Reno. Don’t know if she has any left at all. Lots of quartz crystals too. It is now an open pit gold mine.”1 Now, in case you don’t understand the implications of what you just read, listen and learn! For the most part, collectors are simply not interested in collecting these kinds of nondescript micro minerals with uninteresting chemistries. Jack collected a lot of it because he is a knowledgeable collector and realized how unusual the alunite at this locality was. In the end, however, he had to give it all away for lack of storage space in hope that some of it would be preserved in collections.
1 Jack Crowley, USGS Reno, Nevada, personal communication 2003.

Alunite
Georgia, Graves Mountain. “Pale yellow masses of alunite filling small cavities in weathered kyanite quartzite…Tiny quartz crystals and porous masses of gray barite are typically admixed with alunite. The alunite-filled cavities have the shape of tabular barite crystals and presumably resulted from a series of chemical weathering reactions involving pyrite, barite, kyanite and possibly lazulite.”1
1 Mineralogical Record, Vol.16, 1985 p446.

Alunite
Utah, Piute County, Marysvale. Here alunite is “associated with kaolinization of folded early Tertiary volcanic rocks. They have been mined intermittently for several decades.1
1 Dana's System of Mineralogy, Palache, Berman, Frondel, Seventh Edition, Vol. 2, p558



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Rock Currier
Crystals not pistols.



Edited 2 time(s). Last edit at 12/27/2012 08:44PM by Rock Currier.