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Improving Mindat.orgHeteromorphite

4th Nov 2009 09:12 UTCRob Woodside 🌟 Manager

Heteromorphite

Příbram District, Central Bohemian Region, Czech Republic

Some time ago I complained about photos of acicular Heteromorphite and the response has been underwhelming. As far as I know members of the plagionite group are either platy (plagionite, semseyite) or blocky (heteromorphite, fulloppite) and none are acicular. So unless anyone has an analysed acicular heteromorphite I would propose deleting the following photos and their children:

Jamesonite, etc.

Příbram District, Central Bohemian Region, Czech Republic

Heteromorphite, etc.

Příbram District, Central Bohemian Region, Czech Republic

4th Nov 2009 11:07 UTCLefteris Rantos Expert

Hi,

I have thought of this before and tend to agree with Rob. Has anybody ever analyzed these Heteromorphites? There must be some litterature, these specimens from Pribram are considered a classic occurrence for the mineral.

However, the acicular groups look amazingly different from the other minerals in the same series. And the similarity to Boulangerite-like minerals is apparent.

I have made the following two thoughts on these:

1. On the specimen of this material in my collection, as well as on other similar specimens I've seen for sale, I have noticed the presence of some small bright steel-grey Arsenopyrite-like blocky xls occurring sparsely along with Quartz xls, protruding from the mats the acicular mineral. Maybe this is the real Heteromorphite?

2. The name of Heteromorphite in Greek signifies "different form". I don't know exactly why the mineral was named like this. Mindat page on Heteromprphite states:

ετερος for "different" and μορφή "form" in allusion to a proposed dimorph.

Is this stated in the type-description of the mineral?

My though is that the name might stem from the very different form of Heteromorphite, compared to its closely related species. In which case, the acicular Boulangerite-like mineral might be the real Heteromorphite indeed.

Lefteris.

4th Nov 2009 12:37 UTCFrank Keutsch Expert

I agree 100% with Rob. I have analyzed many acicular "heteromorphites," from Pribram, German localities and a Romanian, which I cannot remember off-hand. In nearly all cases they were boulangerite, I think one was a jamesonite, and one of the German (Wolfsberg) ones a dadsonite.

4th Nov 2009 14:57 UTCSimone Citon Expert

Rob, I've found now your mail, sorry for no reply. Frankly, your definition "Heteromorphite is not an acicular mineral" contrasts with much of the more diffused descriptions about this specie, an example below

http://webmineral.com/data/Heteromorphite.shtml

And I received this little example from a good source. But, no problems, supported by analytical investigation, I assume valid this possibility. OK to remove the pic until we have clarity on how this specie appears (if I have time I will try to analyze this mine). Simone

4th Nov 2009 21:34 UTCRob Woodside 🌟 Manager

Lefteris's comments actually spurred me to a literature search with my limited capabilities. My first thought was to check RRUFF as there are usually both old and new references there. Sadly they have no heteromorphite and so no references. Pavel, is there any extra from the verified locality that you posted which could be sent to them? My next attempt was to check vol.1 of Dana 7, still one of the best sulfide references. Amusingly my original copy had fallen apart a long time ago and my used second copy is not far behind. In it the previous owner had crossed out Heteromorphite and noted it identical to Semseyite!!! Any way on Pg 462 under plagionite group it says. "All the minerals of this group are much of the same habit, short prismatic to tabular, and in this respect they are in striking contrast to the acicular and fibrous minerals, jamesonite, boulangerite, meneghinite, and zinkenite which are also sulfantimonides of lead." At the bottom of that page Berman further says. "The name heteromorphite was first applied³ to a mineral not certainly of this group, but later work⁴ has clearly separated this species from plumosite or jamesonite, both of which are acicular in habit and of a different composition." On pg 466 under heteromorphite Berman says, "Name. ετερος, different, and μορφή, form, in allusion to the difference in form between this species, and the supposed dimorphous feather ore from Wolfsberg."

Ref. ³ Zinken and Rammelsberg, Ann. Phys., 77, 240, (1849)

⁴ Pisani, C.R., 83, 747, (1876) and Spencer (1899)

Ramdohr in the 2nd ed. of his Ore Mineralogy on pg 764 under heteromorphite says, "The ore-microscopic properties are still practically unknown, because heteromorphite was often confused with jamesonite, even though it differs strikingly in form from the latter."

I think Frank's results are typical and I thank you for it. When I was a teenager, Brian Edmund (who x-rayed things) sent me a cm sized kerble with xls from Arnsberg and since it wasn't 4x6 cm in size I traded it to L.G Berry at Queen's. He wrote back ecstatically that he had doubted the piece but was amazed that it was the first real heteromophite he had ever seen.

Simone, I appreciate your efforts very much. Let's leave your photo there for now and please let me insert "unanalysed" in the caption until such time that it can be checked.

6th Nov 2009 08:47 UTCSimone Citon Expert

Rob, first a search on the literature is the right way, so I add a (bad) translation from the text "Carlo M. Gramaccioli, Conoscere i minerali : i solfosali, De Agostini, Novara 1985", a very good source for the sulphosalts: " Heteromorphite forms blocky crystals, imperfect, lead gray, prismatic, elongated and with sharp edges (wedge shaped). The specie was first observed (1876) in the Arnsberg antimony mines in Westphalia, partly in compact form, some as distinct crystals associated with Sphalerite, within a few cavities. Then (1967) Heteromorphite was observed in Kara Kamar in Tajikistan, and finally in a sample with Plagionite at Wolfsberg, Harz, interlaminar to this mineral and to Semseyite. There is a considerable confusion in the mineralogical literature, especially in the old one, with regard to the nature of the specie, however, in recent studies (1969) have verified as valid and belonging to the Plagionite group”. (Unfortunally without pics). Note that the term "elongated" in relation to prismatic crystals may create, from a purely logical point of view, this situation: quite elongated crystals + quite small crystals = acicular habitus, a situation that occurs in the sulphosalts (think about the Meneghinite) and others (think about Arsenopyrite, Glaucodoto, Loellingite ...). I add another web-reference for the "acicular Heteromorphite" with regard to the sample in photo: http://www.mineralienatlas.de/lexikon/index.php/MineralData?mineralid=1580 (I could swear I read yesterday "acicular" in the description on this page, now I do not see more ... is the Woodside effect?).

You do not think I want to contradict your assumption, but how can all these rich and beautiful samples, also from museums, have been classified as Heteromorphite, initial analysis wrong and then continued wrong relations? Ciao. Simone

PS. My sample is not significative and the photo is ugly, you can delete...

6th Nov 2009 18:45 UTCRob Woodside 🌟 Manager

Simone, thank you very much for your researches and good translation. I think you are are right about people intrepreting elongated and small as acicular. Such an intrepretation may be assisted by some rare species collectors ovewhelming desire to own one. This has certainly been aided by the checkered history of this species. The feather ore specimens are lovely and once the misidentification seeps into Museum display collections it is very hard to correct.

As a collector and mineralogical cheerleader, I am honoured to have an effect named after me.X( The effect appears to be some combination of thoughtlessly repeating false information and outright memory errors.B)- It is characterised by a dogged insistance on the truth of the error until faced with good evidence to the contrary.::o. So yes, your belief that "acicular" occurred on that page would be a good example.;)

I'm told that we are not short of storage space, so I'll banish these photos to the user only galleries with the complaints intact and a reference to this thread in the captions. I dislike messing with other's photos, so this is the most I can bring myself to do and I'll leave it to the owners to delete them, if they so wish.

6th Nov 2009 22:37 UTCRock Currier Expert

Rob,

Would you write this one up for Best Minerals before all this good information gets lost in the forum archives?

8th Nov 2009 22:24 UTCRob Woodside 🌟 Manager

Sure, but's what holding me up is my personal predjudice about the Plagionite group. I think these were among the first species recognized as a homologous series differing only by the thickness of the slab of PbS in the structures. Now that polytypes are well known and no longer a hot research topic, he IMA, in its infinite wisdom, has decreed polytypes to be mere crystallographic varieties and not species definers. Homologus series, on the other hand, with advances in technology are now (or recently have been) a hot research topic and regarded as species definers. In my perfect world they should just be regarded as crystallographic varieties. So I'm conflicted about writing a best stuff piece on Plagionite group or 4 pieces on each of the members. Thanks to Herja, Semseyite is the commonist and best known member, so maybe I should do something like I did with Polybasite so that the article would be on Semseyite where the general blurb talks about the other group members? There are only a half dozen localities where decent specimens of this group occurred.

8th Nov 2009 23:13 UTCRock Currier Expert

What you just wrote should be placed in the article(s) as well.Many people in the real world disagree with formal IMA policy(s) and since we want to pay attention to the real world, we need to talk about this stuff. We could also accommodate someone who wanted to defend the IMA policy and let them do a counter argument and put them both in the article and let the user decide.

9th Nov 2009 00:03 UTCRob Woodside 🌟 Manager

OK How about a piece on Semseyite talking about all 4 and when done we could have merely links from the other 3? Should we put such links to the polybasite group members to the polybasite article? I still have to get around to plagiarizing more material on Arizpe, etc. for that piece. Later if someone wants to do a stand alone piece, on say pierceite, that would be fine. I heartily agree with you that on contoversial matters, it is best to give both sides and let the readers decide for themselves. However, no matter how wrong headed the IMA might appear to be on any issue, their decisions must be respected to avoid chaos and for Mindat to remain credible.

9th Nov 2009 10:29 UTCRock Currier Expert

Bob, that sounds OK. We really don't yet know or have a policy about how to handle problems like this. Write the article on Semseyite and then put in the other minerals with links to it. Lets see how it works and what kind of feed back if any from mindaters and lurkers. We can certainly change it around and modify it easily enough if we later thinks it needs to be changed or modified. One of the advantages of working in a format like this. At least we will get something up there for people to reference and a place where additions and changes can be made. It should certainly be better than anything we and may eventually be the best general guide for those species that is available. Or at least that is what we should hope to achieve.

10th Nov 2009 12:37 UTCSimone Citon Expert

Ho, ho, ho, Rob! Again on my specimen (really labeled as Heteromorphite in acicular, blackish crystals, in German), with more attention (and with regard to the point 1 of the Lefteris message). The sample is composed of granular quartz mixed with a deep yellow sulfide (Chalcopyrite?) and red-orange, brilliant Sphalerite (?). The acicular blackish mineral is dark gray to blackish and seems a bit flattened, very small (under 1 mm).

But larger >:D<, about 2 mm, there are some Arsenopyrite-like crystals, blocky, pale gray (a touch of yellow on the surface probably because of Chalcopyrite), wedge-shaped, sometimes prismatic elongated, even if very small (see the latest photos ).

At this point, initially misled by the label and many descriptions mostly found on the web, I tend to think that this is the real Heteromorphite, at least on my piece. What do you think? Simone

10th Nov 2009 17:32 UTCRob Woodside 🌟 Manager

Simone, Good work!!!. That is more believable. I'm happy to put one or more of these photos back in the general gallery with the tag "(unanalysed)" until you can get it analysed. I do remember my Arnsberg piece being more grey than black, but Fullopite is quite black as are some Semseyites.

10th Nov 2009 20:18 UTCLefteris Rantos Expert

Hi,

That's what I was talking about;)

My specimen also has free-standing such xls, protruding from matted aggregates of the acicular mineral that was believed to be Heteromorphite.

However they could be simply Arsenopyrite or the like.

Lefteris.

10th Nov 2009 22:27 UTCRobert Meyer Manager

Rob,

Occasionally, a mineral species might be named in honor of a mineral collector or mineral enthusiast, but I can think of few instances where an effect is so named after a mineral collector. Most of the effects out there are named after physicists and such. Hmm, I wonder . . .

In this case, the Woodside effect must be to go back and check your reference again, because your memory might be wrong--especially when prompted by a contrasting opinion from an authority on the subject.

My memory of the homologous series containing semseyite, plagionite, fülöppite, and heteromorphite, was that they are visually indistinguishable. This would tend to argue against an acicular form of one of these species. I would tend to doubt any unanalyzed occurrence of the latter three species. As I recall, you would need a quantitative chemical analysis or XRD to distinguish between these species. Now, I wonder if I should go check the references against my memory.

Bob

11th Nov 2009 13:28 UTCFrank Keutsch Expert

Bob,

I think your memory is correct. Does that effect have a name? One of the habits of plagionite at the San Jose mine is such that it looks very much like the famous semseyites from Romania. My fulloppite xxs do look blacker than most semseyite and plagionites, but I only have pieces from one locality, so I am not sure I can draw conclusions from this... For this group, I usually like to see XRD...

Frank

11th Nov 2009 23:41 UTCRob Woodside 🌟 Manager

Thanks Bob, that a far more charitable definition of the effect.

I agree with you and Frank 100% about their visual indistinguishability and this is one of the reasons I think they all ought to be varieties.

12th Nov 2009 01:45 UTCAlex Homenuke 🌟 Expert

Re: The Woodside Effect

Hey Rob, here's a Boulangerite created in your image in the Hornicke Museum in Pribram. Note how well groomed it appears compared to the "Heteromorphite" (I assume from this thread that this is not heteromorphite?). I'm close to having our recent Europe tour photos edited and will put a show together for our next mineral meet. That was about 10 mineral and mining museums. The best Pribram pictures I've seen are in Hyrsl and Korbel's book on Czech and Slovak minerals (German text). This has been a most interesting thread.

Cheers, Al

12th Nov 2009 05:01 UTCRob Woodside 🌟 Manager

Thanks Alex. As Lefteris remarked and Simone is hoping, there might be some Heteromorphite buried under all that. Once this sort of incorrect labelling starts showing up in Museum displays it becomes very hard to correct. Both pieces you photoed look like Boulangerite and both have had a bad hair day!!! Christopher's and Manfred's photos above look like Jamesonite. However, probes or x-rays are needed to really nail the feather ores as well. I'm really looking forward to our next get together.

12th Nov 2009 18:21 UTCFrank Keutsch Expert

This does not really belong in this thread, but one of the things I get annoyed about with respect to somewhat fibrous sulfosalts is that everything from the San Jose mine is always sold as zinkenite, whereas a lot of them are jamesonite! In fact, out of a vast amount of material from there, the only one that I had for the longest time that was zinkenite is one specimen with chalcostibite XX. However, zinkenite is common together with the relatively recent andorites.

Frank

12th Nov 2009 18:46 UTCRob Woodside 🌟 Manager

Right on Frank!!! I'm wondering if we shouldn't insist on people labeling their photos as to whether or not visually indistinguishable stuff is analysed and by what method.

13th Nov 2009 12:02 UTCSimone Citon Expert

Or establish a "reliability scale" about listings ...

But first we must define which species are surely indistinguishable.

19th Nov 2009 15:20 UTCSimone Citon Expert

Rob, I updated the Plagionite group in my gallery, please, take a look. Next step is the analysis on the Pribram material...

Lefteris, really your "1.3cm radiating aggregate of lustrous bladed crystals" is "on semseyite matrix" ? (Not Galena matrix or so?)

Regards! Simone

19th Nov 2009 15:28 UTCSimone Citon Expert

Oops, the original doubtful photo, for the documentation of this post.

19th Nov 2009 17:03 UTCLefteris Rantos Expert

Oops, I meant Sphalerite matrix! I just changed it. And it's Sphalerite, not Galena.

Thanks Simone!

Lefteris.

19th Nov 2009 17:05 UTCRob Woodside 🌟 Manager

Thanks Simon. Those are good photos. The Dawsonite is sweet!!!

I updated the plagionite group.

13th Sep 2016 13:50 UTCUwe Kolitsch Manager

Recently analysed a "heteromorphite" from Příbram:

Interlocking sprays of dark grey needles, up to ~4 mm, on small quartz crystals] “Příbram, Böhmen, CSSR”, (label also says: [purchased from] “Dr. Krantz, Bonn VI/84”

SXRD: -> Zinkenite

Zinkenite seems to be new for Příbram?

I'll point Příbram specialist Pavel Skacha to this thread.

EDIT: Misprint

27th Sep 2016 14:06 UTCPavel Skacha Expert

Hi Uwe, thanks,

most of the "jamesonite" and "heteromorphite" (heteromorphite is very doubtful phase at all) specimens from Příbram are in fact boulangerite. Jamesonite is very rare there. Zincenite has been found as massive or finegrained aggregates, I never saw crystals from Příbram. Some specimens came from the Lill shaft, very small amount from the Rudolf shaft in Bohutín. Would you be so kind and post a photo here or to my email? I am mostly interested in overall look of the sample.

Thanks

Pavel

27th Sep 2016 16:18 UTCUwe Kolitsch Manager

Hi Pavel,

Thanks for the reply. Will ask Harry Schillhammer to make a good photo.

BTW, "green" in the description should of course read "grey".

18th Sep 2018 09:27 UTCUwe Kolitsch Manager

Photos (close-up and full-view) of the zinkenite uploaded in the meantime.

https://www.mindat.org/photo-906663.html

NOTE: Příbram specialist Pavel Škácha thinks that the locality is uncertain; although the specimen could come from Bohutín, it more probably comes from a locality outside the Czech Republic.

[This comment added to photos.]

Do these photos ring a bell with anyone? Are some French or German localities possible?

8th Jan 2023 07:45 UTCHubertus (Hu) Hühne

I have to confess I didn't read the whole thread, so pardon me, if I missed something. Here are some pictures of a specimen that we recently acquired, labelled as 'Heteromorphite' from Pribram. On those the crystals (up to about 5 mm long) don't appear 'acicular' to me, rather 'lath-shaped' with striations and shiny golden iridescence. Can it be that this is really Heteromorphite? What else is possible? What I didn't see in the discussion is, that nobody questions the locality given on the labels. Maybe it's just a mix-up of those and the specimen is really from Jáchymov? The Zinkenite sample doesn't look similar to me. I'd certainly exclude Boulangerite and Jamesonite. Emplectite maybe? Stromeyerite? Well, I think I'll have it analysed ...

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