Millerite

Harjo

thinking about this a bit more, probably the most important coalfield locations are coed ely, wyndham, deep navigation, ferndale, gelli and international. all produced good specimens in reasonable numbers

it is difficult to say which is best, because you only know about specimens that are recovered, not what got away! but with that proviso, deep navigation produced probably the best individual specimens closely followed by ferndale (the ironstones at the latter were particularly large giving a high attrition rate when attempting to collect there). gelli also produced some fine specimens in it's own right, but the association here with siegenite, whilst a not uncommon mineral in the coalfield, is much richer than elsewhere. coed ely, wyndham and international were probably the most prolific locations.

when you decide what locations you want to use, i'll add some details for the individual sites where necessary. i can probably get better pictures too.

cheers

ian

Thanks guys for your valuable input, no concert tonight so I'll update the article.
Ian, in the article I used Coed Ely, Deep Navigation, Ferndale and Markham, so, if you can get extra info and/or pictures from specimens from these localities that would be great.

Cheers

Harjo



Edited 1 time(s). Last edit at 04/02/2009 08:09PM by Harjo Neutkens.

hi Harjo

[www.mindat.org] is good to illustrate the history of the area if you want. the plate is from one of my "sowerby's" and dates to 1808

gelli really needs to be there, it is a much more important location than markham

for gelli either [www.mindat.org] or [www.mindat.org], or [www.mindat.org] to illustrate siegenite with the millerite.

both wyndham and international also rank well above markham. don't necessarily think that they have to be there, but if you do use either, then for wyndham [www.mindat.org] or for international [www.mindat.org]



cheers

ian

David, thanks, I had two Canadian localities in the article but somehow they disappeared during last night copy-paste actions.......I've put them back, have a look, if you can give me info on Thompson mine that would be great.

Ian, I added Gelli, I'm off to a concert now so the rest will follow later.

Cheers

Harjo

Harjo,
I have rewritten the introductory remarks for the Best Minerals project. It included what we are trying to do as well as a new section devoted to the format we are currently using, advice for contributors and more. If you have the time read it over and give me your comments, corrections and suggestions. Did you see that Peter has decided to do Millerite?

Rock Currier
Crystals not pistols.

Quote
Rock
Did you see that Peter has decided to do Millerite?

, no, I haven't....??

I have decided to do greenockite. I don't remember to have said anything about doing millerite. :S

Woops, I think that mixup was my fault. My bad!

Rock Currier
Crystals not pistols.

I would like to have your help here though Peter ;) , could you write a couple of lines on the Ruhrgebiet localities in the article, I think that they deserve some information.
That is, if you have time to do that and if you like to, no haste, any help is very much appreciated.

Harjo,
i will try to add info on Saar coal basin millerites soon ..... found the old Paul Guthörl article (Mineralien des Saarbrücker Steinkohlengebirges) yesterday. As millerite occured in almost all coal mines there i would suggest to summarize under [www.mindat.org]
Pictures of some millerites from there to follow.
BTW i´d also suggest to summarize the Ruhrgebiet coal basin for the same reason. I added a millerite picture from Ewald mine also: [www.mindat.org]

Cheers
Roger

Thanks Roger!

What I would like to do with the Ruhrgebiet and the Saarland coalmining areas is something like we did with Wales; Ian's article is prominent as an overview of the area followed by specimens and description of the most prolific mines.
Would that be OK with you?

Cheers

Harjo

Hi Harjo,
just finished the Saar coal basin summary for millerite. There may be the need to "polish" the english a bit (no native speaker) and the pictures are still missing (except one). Hope the text is useful, i tried to get close to the structure of Ian´s article but with general historic remarks first.

Here we go

The coal of the Saar coal basin has been mined for a long time with a first reference from the 14th century. The coal seams are of carboniferous age and were formed in an intramontane through and they are of limnic origin (in contrary to the Ruhr coal which is paralic). The seams are hosted by conglomerates, sandstones, siltstones and shales of the Westphalian C and D to the Stephanian C. Their average thickness is approx. 1,7 to 1,8 m.
The area where the coal was mined extends from Faulquemont and Folschviller in the southwest via Merlebach (all in Lorraine, France), to the german side with the Warndt, Völklingen and Saarbrücken to Neunkirchen and Bexbach in the northeast. During the 19th century hundreds of shafts were working and at the end of the century larger mines were established like the sites of Camphausen, Brefeld und Maybach. Due to the technical development the extraction tonnage increased - only interrupted by World War I, the economy crisis in the 1930s and shortly after World War II - to reach a peak of 17.2 million tonnes in 1955. From 1957 the coal crisis - caused by the increasing use of oil and the cheaper imported coal - led to the close-down of numerous mines and to a consolidation of smaller sites to larger combined mines. In
1968 only 5 mines were left: Ensdorf, Warndt/Luisenthal, Göttelborn, Reden and Camphausen. The latter was closed as a discrete mine and consolidated with Reden and Göttelborn to form the "Verbundbergwerk Ost" (combined East mine) in 1995. This mine was equipped with the worldwide highest headframe - and closed in 2000. In 2005 mining at the Warndt/Luisenthal mine ended and after the closing of the privately owned small scale Fischbach mine end of 2008 only one active mine was left: the "Bergwerk Saar"(Saar mine) in Ensdorf which is operated by the Deutsche Steinkohle AG (DSK). Due to mining-induced seismicity resulting in earthquakes the extraction of the Saar mine had to be reduced in 2008 from 15.000 t per day to almost a third. The closure is determined for the year 2012. Over the centuries approx. 1.5 billion tonnes of coal have been extracted.

During active mining quite a lot of mineral specimens were recovered in the Saar coal basin. The sand- and siltstone host rock contains smallscale hydrothermal mineralization in clefts and small veinlets as well as the coal itself locally was mineralized by hydrothermal fluids. Similar to other coal basins also ironstone geodes - consisting of clayey siderite concrections - contained epigenetic mineralization in shrink crevices. The mineralization is quite uniform. Most common non-metallic minerals are carbonates like Siderite, Dolomite, Ankerite and Calcite, also Baryte and Quartz occurred. Sulphides are Pyrite, Marcasite, Sphalerite, Chalcopyrite, more rare Galena and Linnaeite. An overview of the minerals of the Saar region coal mines was given by WILLERT (1914, cited by GUTHÖRL 1963). Most specimens were not very spectacular and can be looked upon as locality specimens but the Millerite samples were outstanding.

The occurrence of Millerite led to the the first scientific research on Saar coal basin minerals by STEININGER (1819). He describes hairlike crystals associated with siderite/ankerite ("Braunspath" ), pyrite and sphalerite. They were found in a newly opened coal mine in the "Friedrichsthal" in 1806". JORDAN (1854, cited by GUTHÖRL 1963) also reported Millerite formed in crevices of sphaerosiderite on siderite crystals. At that time Millerite was known from the Jägersfreude, Dudweiler, Sulzbach, Friedrichsthal and St. Ingbert mines. Also during railway construction Millerite was found. Probably the best specimens were recovered at the Brefeld mine. GUTHÖRL (1963) reports that he obtained Millerite specimens from that mine with needles up to 60 mm lenght from the Hoffman collection for the geological collection of the Saarbrücken mining academy in 1944. They were associated with Ankerite and Chalcopyrite. Unfortunately most of the samples were lost during a bombing in WW II. GROTH (1878) also describes Millerite from the Dechen and Dudweiler mines occurring in needles of more than 1 Zoll (inch) lenght.

The most common association of millerite in the Saar coal basin is with Siderite/Ankerite, Dolomite and Chalcopyrite. Specimens with other sulfide minerals like Galena or Sphalerite are more rare. According to GUTHÖRL Millerite was found in almost all mines of the region except Ensdorf/Griesborn, Viktoria and Velsen mines. As a result of the closure of almost all mines no more finds are to be expected. Around 1980 a few Millerite samples were found at the dumps of the Camphausen mine by the contributor (Roger Lang). They consisted of lustrous sprays of acicular Millerites in Siderite covered vugs in siltstone/shale. As most of the dumps are landscaped or covered today new finds are almost impossible.

The millerite occurrences of the french side of the coal basin were not described by GUTHÖRL. In the early 1980s some millerite specimens from Lorraine were offered at a local mineral show. One sample was acquired by the contributor. It was told to originate from the Simon/Wendel mine between Petite-Rosselle and Forbach near the german-french border. It is a large specimen with Siderite crystals covered partly by hairlike Millerite crystals up to approx. 3 cm lenght, accompanied by small Chalcopyrite crystals. Consequentially also the french part of the basin can be considered to have been an important source of millerite specimens in the region.

Millerite specimens from the Saar coal basin are preserved in the geological collection of the Saarland. The collection is based at Landsweiler-Reden at the former Reden mine site. It is a merge of the geological collection of the Saarland University with the inventory of the geological-mineralogical collection of the Deutsche Steinkohle AG (DSK, the successor of the collection of the mining academy (Bergingenieurschule Saarbrücken), later Geologische Sammlung der Saarbergwerke AG). The collection is not at display at the moment (April 2009). According to GUTHÖRL other specimens were kept at the departments of mineralogy at Berlin, Munich and Heidelberg universities.

References:
Groth, P. (1878): Die Mineraliensammlung der Kaiser-Wilhelms-Universität Strassburg. - Strasbourg.
Guthörl, P. (1963): Die Mineralien des Saarbrücker Steinkohlengebirges, Teil 1. - Bergfreiheit, Vol. 28, No. 6, 213-222.
Helfer, M. (1990): Technik im Saarbergbau - Historische Entwicklung und regionale Wirkung. - Saarbrücken.
Hethler, E. 1947: Die geschichtliche Entwicklung des Saarländischen Steinkohlenbergbaus. - Saarbrücker Bergmannskalender 1947, 45-57. Saarbrücken.
Ruth, K.H. (1973): Von den planlosen Kohlengräbereien zum Steinkohlenbergbau an der Saar. - Saarbrücker Bergmannskalender 1973, S. 64-75 - Saarbrücken.
Ruth, K.H. (1986/1): Stollen und Schächte im Steinkohlenbergbau an der Saar (1). - Saarberg 5/1986, 23-38, Saarbrücken.
Ruth, K.H. (1986/2): Stollen und Schächte im Steinkohlenbergbau an der Saar (2). - Saarberg 8/1986, 39-56, Saarbrücken.
Ruth, K.H. (1987): Stollen und Schächte im Steinkohlenbergbau an der Saar (3). - Saarberg 6/7/1987, 31-54, Saarbrücken.
Steininger, J. (1819): Geognostische Studien am Mittelrheine. - Mainz.


Maybe there will be a contributor for the french lorraine coal basin occurrences as i haven´t found any literature available here. I uploaded a millerite picture to the main locality [www.mindat.org].

Cheers
Roger

Great Roger!
And now the photographs
So bald Ich Bilder von Stufen habe werde Ich dein Beitrag einfügen, vielen Dank nochmahl!

Grüss

Harjo

Harjo,
The millerite article is looking very good. Good work.

Rock Currier
Crystals not pistols.

"Great Roger!
And now the photographs
So bald Ich Bilder von Stufen habe werde Ich dein Beitrag einfügen, vielen Dank nochmahl!"

Harjo,

The picture is here: [www.mindat.org]
It actually comes from the French part of the mining area. I have assigned the locality based on the information given in the caption (I grew up in this area).

Thanks Peter and Roger!
I've put Rogers text and the photo in the article (I've made two chapters of it, first the part on the Millerite and second the one on mineralogy, geology and mining history)
I've also put Ian's text about the South Wales coalfield below the specimen photographs rather than before, it's more obvious this way, I also divided it into two chapters, analogue to the layout of Roger article.
Further I added some more photographs.
Have a look and tell me what you think.....

Cheers

Harjo

There is a small but excellent collection of local minerals (and fossils) kept at the Saarberg company headquarters in Saarbrücken that can be visited by appointment.

Thanks Harjo and Peter (part. for the Lorraine 'splitting'

Peter ... the small collection you mentioned: you do not mean the former mineralogical collection of Saarberg opposite to the 'Bergwerksdirektion' in Saarbrücken? .. This one is gone and was relocated to Landsweiler-Reden and not on display at the moment.
I spent quite a couple of hours in this exhibition .... i went to school at Saarbrücken .

Haven´t found my Saar millerite until now .. it is somewhere in a box from the time when i moved my collection.

Will also try to get other Saar millerite pictures,

cheers
Roger

"you do not mean the former mineralogical collection of Saarberg opposite to the 'Bergwerksdirektion' in Saarbrücken? .. This one is gone and was relocated to Landsweiler-Reden and not on display at the moment."

That's the one I meant.

"I went to school at Saarbrücken."

Me too.

Added some more localities....