Since my retirement in 1990, I had the privilege to resume work on new and exciting research topics in a highly friendly atmosphere.

This work has been quite entirely devoted to the study of  Platinum Group Minerals (PGM) and more precisely, to the less known and intractable among them. I designated these  as “unconventional”, in opposition with the conventional PGM, belonging to the better known sulfides, arsenides, metals, alloys, etc. The heuristic concept of “Unconventional PGM”, which by definition will never be widely accepted, nor precisely defined, covers all those compounds (unknown, undefined, fictitious,

mixed...)which contain Platinum Group Elements, but which have not yet acceded to the status of defined PGE-containing mineral species, like the sulfides and alloys. This unlimited group is formed of oxides, hydroxides, halides, organics, and of well known minerals containing minor amounts of PG Elements.

My attention was first turned to that topic when I observed that conventional PGM found in Burundi ultrabasic rocks where surrounded by what seemed to be PGE oxides (Bibl.1). When exploring the literature, I found that such compounds, and especially palladium oxide, had been observed unbeknownst in large quantities in Brazil since 1695, described by a scholar in 1711, correctly determined in 1837, and then neglected (23).

From there on, I went forth to collect fresh and historical (museum) samples, and to examine them jointly under the reflected light microscope, the scanning electron microscope (SEM) and the electron microprobe (EMP) (2). Actually, the crop was very rewarding from the onset, since nobody else had dared to explore systematically and at leisure that improbable field with advanced observational and analytical instruments, in comfortable working conditions.

The bibliographical annex collects the titles of the papers published in that spirit. This list is followed by a list of websites which I have devoted to the same UPGM topic. The latter has become in a few years a respected research domain, with discoveries recorded from practically any PGE ore locality. The “upgm/mguide”-site has now been widely accepted as a basic reference.


A few solid highlights

Pseudo-minerals investigated in detail or discredited
ouro preto=black gold from Minas Gerais-Brazil (23)
irite from Urals-Russia (30)

Mineral species reassessed
palladinite from Brazil and from Congo (16, 22)

PGE-bearing minerals recognized in ores
Shinkolobwe sulfides (27)
Shinkolobwe chloritite (22)
Altered peridotites from Zabargad Island (13)
Pd-Au-Hg bitumen from Nevada (26)

New rhenium-bearing minerals
Rheniite (?), Shinkolobwe (27)
Re-Pb-S-Cl phase, Shinkolobwe (27)

Personal or indirect involvement in accreditations of new mineral species by IMA
luberoite Pd5Se4 (14)
verbeekite PdSe2 (28)
jedwabite Fe7(Ta,Nb)3 (31)
tantalcarbid TaC (31)



Bibliography (1987-2004)

(1) Jedwab, J. (1987): Bref aperçu des minéraux de Pt, Pd et Ir trouvés par microsonde électronique dans les roches du Massif Ultrabasique de Musongati (Burundi). Mus. Royal Afr.Centr. Dépt. Géol.& Min. Rapport annuel 1985-1986, 1987, 83-87.

(2) Jedwab, J. (1989): Hints and tips for finding gold and PGMs (almost everywhere) by SEM/EMP. –In: IAGOD.Commission on ore deposits in mafic & ultramafic rocks. 5th Intern.Platinum Symp. 1-3 Aug.1989. Helsinki. 8.4. (abs).

(3) Jedwab, J. (1989): Ru/Ta alloys and Ru/TaC overgrowths in placer concentrates from the Ural Mountains, USSR. –In: IAGOD. Commission on ore deposits in mafic & ultramafic rocks. 5th Intern.Platinum Symp. 1-3 Aug.1989. Helsinki. 8.5.(abs.)

(4) Leblanc, M., F. Gervilla and J. Jedwab (1989):  Noble metals segregation and fractionation in magmatic ores from Ronda and Beni Bousera lherzolite massifs (Spain, Morocco). –In: IAGOD.Commission on ore deposits in mafic & ultramafic rocks. 5th Intern.Platinum Symp. 1-3 Aug.1989. Helsinki. 4.8. (abs.)

(5) Jedwab, J., Cotelo Neiva, J.M. and Neiva, A.M.R. (1989): Platinum group minerals of ultrabasic rocks from Abessedo, Carrazedo and Valongo (Bragança-Vinhais, Northern Portugal). Memorias e Noticias, Publ. Mus. Lab. Mineral. Geol., Univ. Coimbra. N°107, 65-71.

(6) Leblanc, M., F. Gervilla and J. Jedwab (1989):  Noble metals segregation and fractionation in magmatic ores from Ronda and Beni Bousera lherzolite massifs (Spain, Morocco). Mineralogy and Petrology (1990) 42, 233-248.

(8) Jedwab, J. (1990): Native ruthenium in tantalum carbide concentrates from the Ural Mountains, USSR. Mineralogy and Petrology, 1990, 43, 137-146.

(9) Jedwab, J. (1990): Mineralogy of alluvial platinum and gold from the Lubero region (Kivu, Zaire). –In: Intern. Center for Training and Exchanges in the Geosciences. 15th Colloquium of African Geology. Université Nancy I. 10/13 sept.1990. Abstracts volume. 208.

(10) Leblanc, M., Ceuleneer, G., Al Azri, H. et Jedwab, J. (1991): Concentration hydrothermale de palladium et de platine dans les péridotites mantelaires du complexe ophiolitique d'Oman. C.R. Acad.Sci.Paris, 1991, 312,  II, 1007-1012.

(11) Jedwab, J. (1992): Les minéraux d'éléments platinoïdes au Shaba (Zaïre). Bull. Liaison de la Soc. Fr. de Min. & de Crist. v.4/2, p. 30. (abs.)

(12) Jedwab, J., Pineau, F. et Boulègue, J. (1992): Le carbure de tantale de Nijni Taguil (Oural), ses inclusions et ses minéraux associés. Bull. Liaison de la Soc. Fr. de Min. & de Crist. v.4/2, p. 30-31. (abs.)

(13) Jedwab, J. (1992): Platinum Group Minerals in ultrabasic rocks and nickeliferous veins from Zabargad Island (Egypt). C. R. Acad. Sci. Paris, 1992, 314, II, 157-163.

(14) Jedwab, J., Cervelle, B., Gouet, G., Hubeau, X. and Piret, P. (1992): The new platinum selenide luberoite  Pt5Se4 from the Lubero region, Kivu Province, Zaire. Eur.J. Mineralogy, 1992, 4, 683-692.

(15) Jedwab, J. (1992): A review of platinum occurrences in Zaire (except Shaba). -In: Pohl, W. & Delhal, J. (eds.) Metallogeny of the Kibaran Belt, Central Africa, Intern. Geol. Correl. program, Project 255, IGCP-Project 255, Tervuren & Braunschweig, 4: 101-105.

(16) Jedwab, J., Cassedanne, J., Criddle, A. J., du Ry, P., Ghysens, G., Meisser, N., Piret, P. and Stanley, C.J. (1993): Rediscovery of palladinite PdO from Itabira (Minas Gerais, Brazil) and from Ruwe (Shaba, Zaire). Terra Abstracts, suppl. to Terra Nova, 1993, v. 5, p. 22. (abs.)

(17) Jedwab, J. (1993): Palladium and platinum mineralogy of the evaporitic lower Roan of SW Shaba, Zaire. Terra Abstracts, suppl. to Terra Nova, 1993, v. 5, p. 21-22. (abs.)

(18) Jedwab, J. (1994): Minéralogie du platine, du palladium et du ruthénium dans une strate chloriteuse du gisement de Shinkolobwe (Shaba, Zaïre). Bull. Liaison de la Soc. Fr. de Min. & de Crist. v.6, N°2, p. 28. (abs.)

(19) Jedwab, J. (1995): Oxygenated Platinum-Group-Elements and Transition-Metal (Ti, Cr, Mn, Fe, Co, Ce)-compounds in the supergene domain. Chron. Rech. Min., N° 520, 47-53.

(20) Jedwab, J. (1996): L'or noir du Brésil. -In: Catalogue de l'Exposition: Trésors de la Terre-Du minéral au bijou. Abbaye Saint Gérard de Brogne, 125 p. (p.75-79).

(21) Cassedanne, J. P., Jedwab, J. et Alves, J. N. (1996): Apport d'une prospection systématique à l'étude de l'origine de l'or et du platine alluviaux du Côrrego Bom Sucesso (Serro-Minas Gerais). An. Acad. Bras. Ci., 68 (4), 569-582.

(22) Jedwab, J. (1997):  Minéralogie des Métaux du Groupe du Platine au Shaba, Zaïre. (Communication présentée au Colloque International Cornet, Mons 5-9 septembre 1994) -In: "Centenaire des premières études sur la géologie shabienne (Zaïre): "Gisements de cuivre stratiformes et minéralisations associées", J.M. Charlet ed., Fac. Polytechn. Mons et Ac. Royale des Sciences d'Outremer, 1997, 482 pp. [325-355].

(23) Jedwab, J. et Cassedanne, J. (1998): Historical observations of platinum and palladium oxides in Minas Gerais, Brazil. Canad. Miner., 36, 887-893.

(24) Jedwab, J. (1999): Le platine au Kivu: Mystères, mythes, erreurs et vérités autour du platine de Lubero. Bull. Séances Ac. Royale Sci. Outremer, 45-2, 177-191.

(25) Jedwab, J., Badaut, D. et  Beaunier, P. (1999): Discovery of a Palladium-Platinum-Gold-Mercury bitumen in the Boss Mine (Clark County, Nevada). Economic Geology, vol 94, No.7, 1163-1172.

(27) Jedwab, J., Tarkian, M., Cornelisen, B., Moëlo, Y. and Deudon, C. (1999): Mineralogy of palladium, platinum, rhenium and gold in the sulfidic ores of Shinkolobwe, Katanga, Congo. -In: Mineral Deposits: Processes to Processing, Stanley et al., eds. Balkema, Rotterdam, 171-174. (ext. abs.)

(28) Roberts, A. C., Paar, W. H., Cooper, M. A., Topa, D., Criddle, A. J. and Jedwab, J. (2002): Verbeekite, monoclinic PdSe2, a new mineral from the Musonoi Cu-Co-Mn-U mine, near Kolwezi, Shaba Province, Democratic Republic of Congo. Min. Mag. ,66(1), 173-179.

(29) Power, M. R., Pirrie, D., Jedwab, J. and Stanley, C. J. (2004): Platinum-group element mineralisation in an arsenic-rich magmatic sulphide system, Talnotry, Southwest Scotland. Min. Mag., 68(2), 395-411.

(30) Jedwab, J.  (2004) ‘Irite’ (Hermann, 1836/1841) from the Urals. Min. Mag., 68(2), 369-392.

 (31) Novgorodova, M.L., Generalov, M.E. and Trubkin, N.V. (1997):
[Jedvabite Fe7(Ta,Nb)3-A new mineral in association with tantal-and niobocarbides from Pt-bearing placers] (in Russian, with English abstract). Zap. Vseross. Min. Obchshestvo, 126(2), 1997, p. 100-104. Amer. Min. 1998, 83, p. 654.



Personal observations of UPGM&M under the reflected light and the scanning electron microscopes in worldwide platinum ores 

A bibliographic guide to UPGM&M observed in worldwide platinum occurrences since 1711

Mineralogy and chemical composition of UPGM&M found in ores from the Katanga Copper Belt

Revision of the so-called mineral “irite” found in historical aqua-regia-insoluble residues of Uralian platinum ores 

Magnetite platelets in the Orgueil carbonaceous meteorite

Set of pictures made under the scanning electron microscope of magnetites separated from the Orgueil carbonaceous meteorite.

Early cosmic dust pictures

Reproduction of, and comments on, the first pictures of  “cosmic dust” collected during H.M.S. CHALLENGER’s expedition (1873-1876), and drawn in 1889 by the Belgian petrographer Alphonse Renard:

Eponymie de la « jedwabite » : Genève

Screening tests for native platinum

Bricolage camera numérique pour macro/microphotographie:

Webmaster Benjamin Barbier

Last modification: january 25, 2006