Mindat Logo

Prassoite

This page is currently not sponsored. Click here to sponsor this page.



Formula:
Rh
 
17
S
 
15


Prassoite: the mineral prassoite, Rh3S4, was approved as mineral 70-041 by the CNMMN in March 1971. The author, Kingston, published some data in his Ph.D. thesis in 1977. These data were summarized by Cabri in 1981, but he stated that the true formula might be Rh17S15 (Mandarino, J.A. & M.E. Back (2004), Fleischer's Glossary of Mineral Species: 219).

Augé found the same mineral as Kingston in 1988, with the formula Rh3S4 (Can. Mineral. 26, 177-192), and this paper was mentioned by Jambor in 1989 (Am. Mineral. 74, 1220).

Britvin et al. proposed the mineral Miassite (97-029) to the CNMMN with the formula Rh17S15. This mineral was approved in October 1997, but the name was suspended because of possible problems with prassoite. The authors were asked to contact Kingston. They tried to do so, but to no avail.

After having heard from Britvin et al. that Kingston did not reply to any search, the suspension on the name miassite was lifted, but the CNMMN chairman then made a mistake (probably by not having access to the 1971 archives).

In his Memorandum of July 1999, Joel Grice wrote: 'Prassoite' was never approved by the CNMMN, and no type material can be found. It is apparent that the authors of miassite have done everything possible to establish or
refute the existence of this dubious mineral and the name 'prassoite' is to be discouraged from further usage. In his letter to Britvin et al., lifting the suspension, Joel Grice wrote: I would ask you to make it clear in your publication that all attempts were made to find the type material for a formal discrediation of prassoite but none existed.

Britvin ,et al. published their Miassite in ZVMO 130(2), 41-44 (2001), stating in the paper that prassoite was never approved by the CNMMN, this of course on the authority of Joel Grice. The paper was abstracted by Jambor (Am. Mineral. 87, p. 1511), with the correction that prassoite had indeed been approved by the CNMMN back in 1971.

Later, it became apparent that the type material of prassoite was present in the British Museum (on the same specimen as the type material for kingstonite), but the letters of Britvin et al. to Kingston were never forwarded to the curator of the British Museum.

We have meanwhile the strange fact that there are at least ten papers using the name prassoite (the most recent one in Can. Mineral. 40 (2002), 1127-1146), but only a single paper on miassite!

Moreover, the name 'prassoite' has never been officially discredited or withdrawn.

In view of the delay in the (incomplete) publication of the inadequately described prassoite and the uncertainties about its composition, the name ‘prassoite’ is withdrawn for the time being in favour of miassite.

Unambigous evidence for the existence of Rh3S4 as a mineral might reinstate the name prassoite.

Re-examination of analyses of the type material indicate that 'prassoite' is actually Ferrorhodsite or Cuprorhodsite (Cabri, pers. comm., reported in Mineralogical Magazine, August 2005, Vol. 69(4), p. 447)

Classification of Prassoite

IMA status:Not Approved
mindat.org URL:http://www.mindat.org/min-25715.html
Please feel free to link to this page.

Chemical Properties of Prassoite

Formula:
Rh
 
17
S
 
15
Essential elements:Rh, S
All elements listed in formula:Rh, S

Other Names for Prassoite

Synonyms:
IMA1970-041
Other Languages:

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Prassoite

Reference List:

- +
Canadian Mineralogist (1988): 26: 177-192.

Jambor (1989), American Mineralogist: 74: 1220.

Bowles, J.F.W. (2000) Prassoite, vysotskite and keithconnite from the Freetown layered complex, Sierra Leone. Mineralogy and Petrology: 68: 75-84.

Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva (2001): 130(2): 41-44. (Miassite)

CIM Special Volume 23: 90, 132.

CIM Special Volume 23: 155.

Jambor, American Mineralogist (2002): 87: 1511.

Canadian Mineralogist (2002): 40: 1127-1146.

Mineralogical Magazine, August 2005, Vol. 69(4), pp. 447-453.

Internet Links for Prassoite

Search Engines:
  • Look for Prassoite on Google
  • Look for Prassoite images on Google
  • Mineral Dealers:
  • The Arkenstone - Fine Minerals
  • Mineral Classics - Worldwide Collector Quality Minerals and Gems
  • Search for minerals at Heliodor
  • Top quality minerals from Kristalle of California
  • Wilensky Fine Minerals
  • Minerals from Darwin Natural History
  • Buy from David K Joyce minerals
  • SpiriferMinerals.com - high quality low prices
  • Rare and Unusual minerals at Mineralogical Research Company
  • webminerals
  • Prassoite specimens for sale - minfind.com
  • Buy RARE Minerals from Rocks of Africa
  • Jobs:
  • Mining & Geology Jobs
  • Localities for Prassoite

    The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Canada
     
    • Québec
      • Chaudière-Appalaches
        • Les Appalaches RCM
          • Thetford Mines
    Pagé et al. (2001) GSA 2001 NE program abstracts;
    New Caledonia
     
    • Southern Province
      • Ouen Island
    33rd International Geological Congress (2008) session MPM-04 Platinum-group mineralogy: Platinum-group minerals in chromitite schlieren from the ouen island, new caledonia ophiolite
    Russia
     
    • Urals Region
      • Middle Urals
    9th International platinum symposium Chromite-PGE mineralization in the Uktus Alaskan-Type Complex (Central Urals,)
    Sierra Leone
     
    • Guma Water
    Mineralogy and Petrology (2000): 68: 75-84 .
    Mineral and/or Locality
    Search Google
     
    Copyright © Jolyon Ralph and Ida Chau 1993-2012. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
    Current server date and time: 29th Oct 2012 20:24:43
    Mineral and Locality Search
    Mineral:
    and/or Locality:
    Options
    Fade toolbar when not in focusFix toolbar to bottom of page
    Hide Social Media Links
    Slideshow frame delay seconds