Hi, [www.mindat.org] This photo shows an acicular sulphosalt, labeled as Schirmerite. The locality is not listed for Schirmerite and there is no mention if the sample is analyzed. Although these sulphosalts are absolutely impossible to distinguish without analysis, a very similar specimen from the same locality has been analyzed as Sb-rich Gustavite [rruff.info] . Please not that the analyzed specimen in the RRUFF website was also previously labeled as Schirmerite!! (see the "view label" link) I think that at least a note should be added to the caption, stating that the sample is not analyzed and it's ID is questionable. Lefteris http://www.mindat.org/forum.php?read,7,210896,210896#msg-210896 Fri, 24 May 2013 09:05:36 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,7,210896,265059#msg-265059 http://www.mindat.org/forum.php?read,7,210896,265059#msg-265059
Identification is impossible without XRD analysis or at least quant. EPMA.]]> Uwe Kolitsch Mistakes and Errors Tue, 03 Jul 2012 12:03:13 +0000 http://www.mindat.org/forum.php?read,7,210896,264750#msg-264750 http://www.mindat.org/forum.php?read,7,210896,264750#msg-264750 Uwe Kolitsch Mistakes and Errors Fri, 29 Jun 2012 16:11:12 +0000 http://www.mindat.org/forum.php?read,7,210896,264434#msg-264434 http://www.mindat.org/forum.php?read,7,210896,264434#msg-264434
Sb: 121.76 g/mol
Bi: 208.98 g/mol
Pb: 207.2 g/mol
Ag: 107.87 g/mol
S. 32.06 g/mol

Thus we get:

Bi : Sb : Pb : Ag : S = 0.114: 0.066 : 0.052 : 0.056 : 1.600]]> Peter Haas Mistakes and Errors Mon, 25 Jun 2012 17:49:42 +0000 http://www.mindat.org/forum.php?read,7,210896,264431#msg-264431 http://www.mindat.org/forum.php?read,7,210896,264431#msg-264431
What we can also safely assume, is that your specimen is indeed strongly Bi-dominant, i.e. Schirmerite or Gustavite, and NOT Terrywallaceite or some other new Sb-dominant species.

Lefteris.]]> Lefteris Rantos Mistakes and Errors Mon, 25 Jun 2012 16:41:16 +0000 http://www.mindat.org/forum.php?read,7,210896,264376#msg-264376 http://www.mindat.org/forum.php?read,7,210896,264376#msg-264376 Rob Woodside Mistakes and Errors Sun, 24 Jun 2012 21:00:14 +0000 http://www.mindat.org/forum.php?read,7,210896,264375#msg-264375 http://www.mindat.org/forum.php?read,7,210896,264375#msg-264375 Results:
Pb: 10,8%
S: 51,3%
Sb: 8%
Bi: 23,8%
Th: 6% (Th???)
(Could the Th peak being mistaken? Is it a Ag peak?)

Can anybody tell me what it might be?

Marko]]> Marko Burkhardt Mistakes and Errors Sun, 24 Jun 2012 20:36:12 +0000 http://www.mindat.org/forum.php?read,7,210896,239478#msg-239478 http://www.mindat.org/forum.php?read,7,210896,239478#msg-239478
Your point about the Lillianite Group being difficult to identify and many minerals specimens existing under "false flags" is well taken.

The chemical analyses by Dr. Karup-Moller in his 1977 investigation of type Schirmerite gave three discrete clusters of analyses on a Bi2S3-Ag2S-Pb2S2 triangular plot. They plotted along a constant Ag2S tie line.

Part of the problem with the mislabelling may be the age of some of the samples. Schirmerite was originally characterized by Dr. Genth and his paper on the description indicates he had great difficulty distinguishing Schirmerite as all the data available to him was wet chemistry.

The Treasury Mine is fairly simple in its sulphosalt mineralogy. The Ag-Bi veins are physically separate from the Galena-bearing Pb-Ag veins. Schirmerite only occurs in the Ag-Bi veins.

Richard Gunter]]> Richard Gunter Mistakes and Errors Wed, 26 Oct 2011 15:06:19 +0000 http://www.mindat.org/forum.php?read,7,210896,239466#msg-239466 http://www.mindat.org/forum.php?read,7,210896,239466#msg-239466
Just take a look at specimens of Gustavite, Cosalite and Krupkaite that have been positively identified by the RRUFF project ( [rruff.info] ): most of them were labeled as something different on their previous labels!

Indeed, type-locality Schirmerite from Colorado looks completely different from the Peruvian material. However this doesn't mean that Schirmerite can not occur in a habit similar to other species of the Gustavite-Lillianite series (free-standing bladed xls) at a different locality. I'm not saying that this makes the Peruvian material true Schirmerite, just that it doesn't exclude this possibility.

Also, the formula of Schirmerite could probably incorporate some Sb replacing Bi, as long as Bi remains dominant (someone more knowledgeable of the complex mineralogy of sulphosalts might correct me here, as incorporation of Sb could at some extent change the structure?). So we could not exclude the existence of a Sb-bearing Schirmerite, even if type-locality material is actually Sb-free. Also, variable Pb/Bi ratios could result in different species (or a mixture of species): As noted before, the difference between Schirmerite and Gustavite (and several other closely related species, for that purpose) is the thickness of a PbS sheet in the structure, i.e. the Pb/Bi ratio.

Marko - an analysis would certainly shed light to the situation here. Everything else is mere guess at this point...

Lefteris.]]> Lefteris Rantos Mistakes and Errors Wed, 26 Oct 2011 09:24:27 +0000 http://www.mindat.org/forum.php?read,7,210896,239442#msg-239442 http://www.mindat.org/forum.php?read,7,210896,239442#msg-239442
These "Schirmerite" crystals from Peru do not look too much like the type locality Schirmerite. The Schirmerite crystals are tin-white laths in Quartz that have a coating of a fine-grained, black alteration product. The Colorado Schirmerite crystals do not contain any Sb but have variable Bi-Pb ratios. I do not know why but it may be due to short-range disequilibrium.

Richard Gunter]]> Richard Gunter Mistakes and Errors Tue, 25 Oct 2011 22:42:01 +0000 http://www.mindat.org/forum.php?read,7,210896,239234#msg-239234 http://www.mindat.org/forum.php?read,7,210896,239234#msg-239234
My sample has exacty the same label. If there is no mix-up of the labels, it is probably Terrywallaceite. An analysis will be helpfull, I guess.

Marko]]> Marko Burkhardt Mistakes and Errors Sun, 23 Oct 2011 16:52:00 +0000 http://www.mindat.org/forum.php?read,7,210896,239169#msg-239169 http://www.mindat.org/forum.php?read,7,210896,239169#msg-239169 rruff.info] ) also has a prior label of "Schirmerite".

It's a very thin line between Sb-rich but Bi-dominant Gustavite (such as [rruff.info] ), and Sb-dominant Terrywallaceite.

Schirmerite is also Bi-dominant, but has a thicker PbS sheet than Gustavite in the structure. A Sb-dominant phase would make a new species, I believe.

Lefteris.]]> Lefteris Rantos Mistakes and Errors Sat, 22 Oct 2011 20:36:58 +0000 http://www.mindat.org/forum.php?read,7,210896,239162#msg-239162 http://www.mindat.org/forum.php?read,7,210896,239162#msg-239162 When my sample was sold as Schirmerite, he sold some Sb-rich Gustavites at the same time. These Sb-rich Gustavites turned out to be the Terrywallaceite.
But I once got the information that there was some analysis about the "Schirmerite" running and it perhaps will also turn out to be a new mineral.
That's all I know at the moment.

Marko]]> Marko Burkhardt Mistakes and Errors Sat, 22 Oct 2011 19:08:44 +0000 http://www.mindat.org/forum.php?read,7,210896,239135#msg-239135 http://www.mindat.org/forum.php?read,7,210896,239135#msg-239135
This might be the new species Terrywallaceite (IMA 2011-017). See [rruff.info]

Lefteris.]]> Lefteris Rantos Mistakes and Errors Sat, 22 Oct 2011 14:26:47 +0000 http://www.mindat.org/forum.php?read,7,210896,216182#msg-216182 http://www.mindat.org/forum.php?read,7,210896,216182#msg-216182 Uwe Kolitsch Mistakes and Errors Mon, 07 Mar 2011 16:01:40 +0000 http://www.mindat.org/forum.php?read,7,210896,216128#msg-216128 http://www.mindat.org/forum.php?read,7,210896,216128#msg-216128
I got some new information today. This mineral is not really Schirmerite. The last analysis show that it is also not Sb-rich Gustavite. Some more analysis is done and will be done. Publication will come soon.

Marko]]> Marko Burkhardt Mistakes and Errors Sun, 06 Mar 2011 22:12:17 +0000 http://www.mindat.org/forum.php?read,7,210896,210991#msg-210991 http://www.mindat.org/forum.php?read,7,210896,210991#msg-210991
I will try to get more information. It was sold as "analyzed" Schirmerite, thats all I can tell at the moment.

Marko]]> Marko Burkhardt Mistakes and Errors Wed, 19 Jan 2011 22:08:47 +0000 http://www.mindat.org/forum.php?read,7,210896,210941#msg-210941 http://www.mindat.org/forum.php?read,7,210896,210941#msg-210941 Rob Woodside Mistakes and Errors Wed, 19 Jan 2011 18:33:33 +0000 http://www.mindat.org/forum.php?read,7,210896,210896#msg-210896 http://www.mindat.org/forum.php?read,7,210896,210896#msg-210896
[www.mindat.org]
This photo shows an acicular sulphosalt, labeled as Schirmerite. The locality is not listed for Schirmerite and there is no mention if the sample is analyzed.

Although these sulphosalts are absolutely impossible to distinguish without analysis, a very similar specimen from the same locality has been analyzed as Sb-rich Gustavite [rruff.info] . Please not that the analyzed specimen in the RRUFF website was also previously labeled as Schirmerite!! (see the "view label" link)

I think that at least a note should be added to the caption, stating that the sample is not analyzed and it's ID is questionable.

Lefteris]]> Lefteris Rantos Mistakes and Errors Wed, 19 Jan 2011 14:43:06 +0000