Learning Center What is a mineral?The most common minerals on earth Information for Educators Mindat Articles The Elements The Rock H. Currier Digital Library Geologic Time

Minerals by Properties Minerals by Chemistry Advanced Locality Search Random Mineral Random Locality Search by minID Localities Near Me Search Articles Search Glossary More Search Options

The Mindat Manual Add a New Photo Rate Photos Locality Edit Report Coordinate Completion Report Add Glossary Item

Mining Companies Statistics Users Mineral Museums Clubs & Organizations Mineral Shows & Events The Mindat Directory Device Settings The Mineral Quiz

Photo Search Photo Galleries Search by Color New Photos Today New Photos Yesterday Members' Photo Galleries Past Photo of the Day Gallery Photography

Discussions

💬 Home 🔎 Search 📅 Latest

╳Discussions

💬 Home 🔎 Search 📅 Latest

Groups

Recent Images in Discussions

Improving Mindat.orgProblems with search by elements

19th Nov 2014 18:01 UTCReiner Mielke Expert

Not sure if this is a mistake or a deficiency in the system, however the only essential elements in this http://www.mindat.org/min-3506.html are Cu and S, but when I search by chemistry for minerals with Cu and S only, Sakuraiite does not come up?

19th Nov 2014 18:13 UTCDavid Von Bargen Manager

Second from bottom.

19th Nov 2014 18:19 UTCUwe Kolitsch Manager

"with Cu and S only"

19th Nov 2014 18:28 UTCReiner Mielke Expert

I realize that "only" is the problem but "only" should work shouldn't it? Finding out 300 + minerals can contain Cu and S not very useful.

19th Nov 2014 18:32 UTCTom Tucker

Reiner, on the page with the periodic table, where you are selecting Cu and S, there's a button to "exclude all other elements". Then run the search - you get nine copper sulphide minerals.

19th Nov 2014 18:37 UTCReiner Mielke Expert

Hello Tom,

Yes, but like I said, Sakuraiite is not one of them.

19th Nov 2014 18:40 UTCTom Tucker

Reiner, that's because it's formula indicates it may also contain Zn,Fe,In, and Sn - not just Cu and S. Tom

19th Nov 2014 20:23 UTCReiner Mielke Expert

But Tom, Zn,Fe,In, and Sn are not essential components, in other words you can have Sakuraiite that contains only Cu and S so it should come up if you search only on Cu and S. Sphalerite commonly contains Mn,Cd,Hg,In,Tl,Ga,Ge,Sb,Sn,Pb, &/or Ag but if I search only on Zn and S sphalerite comes up. The problem is the system does not search on the essential elements and it should.

19th Nov 2014 21:07 UTCTom Tucker

Reiner, I guess I don't know. Mindat has sphalerite as ZnS, ( as does the IMA ) with nothing else essential, however Anthony et al (1990) has sphalerite as (Zn,Fe)S. I suspect that sakuraiite has essential Cu, with the other metals as "impurities". If not, then couldn't sakuraiite be just FeS, or SnS ? I'm sure that's not intended - there must be some other essential element. Or similarly, there could be a pure end member of FeS - sphalerite. I see that the IMA has sakuraiite as: (Cu,Zn,Fe)3(In,Sn)S4, so apparently some quantity of In or Sn is essential. Maybe the formula on Mindat needs correcting.

19th Nov 2014 21:10 UTCReiner Mielke Expert

Looks like Mindat's formula and info needs correcting.

19th Nov 2014 23:39 UTCRob Woodside 🌟 Manager

Done, thanks!

20th Nov 2014 00:11 UTCAlfredo Petrov Manager

I'd previously thought of sakuraiite as the indium analogue of kesterite rather than sphalerite, but I guess I was wrong. Without any cleavage, it looks more like a stannite-group mineral than a sphalerite group ("looks" not being a determinative factor, I know ;-) ). Has a detailed structure for sakuraiite ever been published?

20th Nov 2014 09:19 UTCUwe Kolitsch Manager

"Zn,Fe,In, and Sn are not essential components, in other words you can have Sakuraiite that contains only Cu and S."

No! (And on what basis do you think they are "not essential"??) Pure sphalerite-type or -based CuS does not exist - the mineral needs the Zn/Fe/In/Sn to become stable. Pure CuS would be simply covellite! Please read http://rruff.info/rruff_1.0/uploads/CM24_679.pdf.

There are numerous examples of minerals which need certain minor elements to become stable.

Formula changed back to (Cu,Zn,Fe,In,Sn)S - which is the formula in the IMA list.

20th Nov 2014 14:25 UTCReiner Mielke Expert

ON the basis of what Mindat has in the database (http://www.mindat.org/min-3506.html), which as you point out is incorrect. I suggest it be corrected. However the Mindat feature for searching by chemistry should also search on essential elements which it currently does not.

20th Nov 2014 14:33 UTCUwe Kolitsch Manager

Reiner: An element after a comma in a chemical formula of a mineral does NOT automatically imply that this element is non-essential!

You have to check the published data for each mineral.

20th Nov 2014 14:36 UTCReiner Mielke Expert

Uwe, "Essential elements" as listed by Mindat are only Cu and S this implies that all others are not essential! If I have to always check the published data then Mindat is redundant!

20th Nov 2014 14:38 UTCTom Tucker

Just pulled this line of data:

Sakuraiite (Cu,Zn,Fe)3(In,Sn)S4 A 1965-017 Japan Chigaku Kenkyu (Earth Science Studies), Sakurai volume (1965), 1 Canadian Mineralogist 24 (1986), 405

off of this Sept, 2014 list of IMA approved minerals:

http://pubsites.uws.edu.au/ima-cnmnc/IMA_Master_List_(2014-09).pdf

20th Nov 2014 14:41 UTCAlfredo Petrov Manager

Programming deficiency: the program interprets only the first element in each parenthetical string as being essential. When there are substitutions that are actually essential to the structure, we would need some way of manually over-riding the program to make sure the Search by Elements function can find them. Not something the management team can do.

20th Nov 2014 14:50 UTCPeter Haas

Plus, we should consider to add an option that searches only in the essential elements field.

20th Nov 2014 14:53 UTCReiner Mielke Expert

Just to add confusion to this the most recent publication AM73 934 states:

and as far as I know this has not been resolved. It would be useful if Mindat had a note to that effect.

20th Nov 2014 15:00 UTCAlfredo Petrov Manager

I think it might have been resolved by the recent approval of ishiharaite (sphalerite structure), leaving sakuraiite with a structure different from sphalerite's (otherwise there would have been no reason to approve ishiharaite)?

20th Nov 2014 15:27 UTCUwe Kolitsch Manager

Tom: You’re right, sorry. I had only checked a prior version from early 2014.

Re-changed and comment added.

Reiner: “this implies that all others are not essential”

No, it does not - you only have the wrong impression it does.

Reiner: “useful if Mindat had a note to that effect.” Comment added.

Personally, I’d rather trust a study which uses both chemical-analytical and X-ray diffraction data (i.e., Kissin & Owens, 1986) than one that uses only chemical-analytical data (Shimizu et al., 1986, published a little bit earlier).

Alfredo: Ishiharaite has an F-centred cubic cell, whereas sakuraiite has a primitive cubic cell.

20th Nov 2014 15:48 UTCReiner Mielke Expert

Hello Uwe:

"Reiner: “this implies that all others are not essential”

No, it does not - you only have the wrong impression it does. "

If only Cu and S are listed as essential, but are not the only essential elements, then the list is incomplete. Would it not be a good idea to list all the essential elements and not just some of them otherwise having such a list would be redundant ?

20th Nov 2014 15:57 UTCUwe Kolitsch Manager

It would be a good idea but only feasible to a certain extent: in many cases (generally rare minerals) not enough analytical and thermodynamic data are known to be completely certain that an element is necessary for stabilisation or just often present in samples due to geochemical or other reasons.

If I search for a mineral species that would fit a certain chemical analysis, I use both the "only element(s), X, Y, ..." option and the "elements X, Y, ... (and any others allowed)". Although the latter might result in several pages of possible minerals, they are checked much quicker than thought, and often yield the correct result.

20th Nov 2014 16:15 UTCReiner Mielke Expert

Well you could enter a X or ? in the essential element field if not certain of all the essential elements. That way one could search on essential elements and greatly reduce the number of possibilities (such as in this case) while at the same time giving an indication that the data is incomplete. As it now stands one does not know if the list contains all the essential elements or not.

20th Nov 2014 17:20 UTCUwe Kolitsch Manager

In professional searchable table-of-the-elements (e.g. in the ICSD database), there are several additional options for searching:

- limit to a certain no. of elements (e.g. min. 3, max. 5 - very handy)

- search among groups of elements (e.g., (any) lanthanide or any alkali element)

- include elements which may be present, but don't have to be

- ... (can't check at the moment)

Don't know how difficult to program such options would be.

21st Nov 2014 08:42 UTCAlfredo Petrov Manager

Ishiharaite has an F-centred cubic cell, whereas sakuraiite has a primitive cubic cell.

Uwe, what's the correct space group for sakuraiite? We should add it to the sakuraiite page.

21st Nov 2014 13:06 UTCFrank Keutsch Expert

Alfredo,

I think questions remain about sakuraiite...

Frank

21st Nov 2014 14:40 UTCReiner Mielke Expert

Getting back to my original complaint, why not allow people to search on either "Essential elements" or "All elements listed"? That would go a long way to reducing the number of possibilities with a search and should not require much of a change in programming.

21st Nov 2014 19:02 UTCUwe Kolitsch Manager

"what's the correct space group for sakuraiite? We should add it to the sakuraiite page."

It's not known (see the link to the mentioned paper).

Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 19, 2024 09:32:54

Go to top of page