Photomicrography > Quartz > with gersdorffite inclusions
First draft: April 4th, 2017 | Last update: April 5th, 2017
Although the crystal inclusions merely reached about 0.2mm in diameter, gersdorffite, NiAsS, was first identified in 1990 by Stalder & Soom in quartz crystals from two locations in Switzerland - Campeiro near Olivone (as of 2006 Blenio) and the Furkabasis tunnel (Stalder & Soom, 1990; Hyrsl & Niedermayr, 2003).
In the second half of the 1990's, material from the southern Urals appeared with single crystals typically measuring 2 to 3mm in diameter and often occurring in clusters. The largest gersdorffite inclusion reported measured a whopping 16mm in diameter (Sokolov & Henn, 1998; Hyrsl & Niedermayr, 2003).
Gersdorffite appears to be quite rare as inclusion in quartz. The quarry near Magnitogorsk is famed for it, but as it closed down, it remains unclear whether or not new material is being found. The samples shown here were purchased on a mineral fair in Tisnov, Czech Republic in May 1996 (Höfelt, 2016).
Interestingly enough, gersdorffite also occurs as inclusions in emeralds from Carnaiba, Brazil and Gravelotte, South Africa (Gübelin & Koivula, 2005).
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Bayliss,P . & Stephenson, N.C. (1968). The crystal structure of gersdorffite (III), a distorted and disordered pyrite structure. Mineralogical Magazine, Vol. 36, No. 283, pp. 940-947. Mineralogical Magazine Tables of Contents
Béziat, D., Monchoux, P. & Tollon, F. (1996). Cobaltite–gersdorffite solid solution as a primary magmatic phase in spessartite, Lacaune area, Montagne Noire, France. The Canadian Mineralogist, Vol. 34, Issue 3 (June), pp. 503-512. The Canadian Mineralogist Tables of Contents
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Fanlo, I., Subías, I., Gervilla, F., Paniagua, A. & García, B. (2004). The composition of Co–Ni–Fe sulfarsenides, diarsenides and triarsenides from the San Juan de Plan deposit, central Pyrenees, Spain. The Canadian Mineralogist, Vol. 42, Issue 4 (August), pp. 1221-1240. The Canadian Mineralogist Tables of Contents
Fanlo, I., Subías, I., Gervilla, F. & Manuel, J. (2006). Textures and compositional variability in gersdorffite from the Crescencia Ni-(Co-U) showing, Central Pyrenees, Spain: primary deposition or re-equilibration? The Canadian Mineralogist, Vol. 44, Issue 6 (December), pp. 1513-1528. abstract The Canadian Mineralogist Tables of Contents
Fukuoka, M. & Hirowatari, F. (1980). On minerals in the system Ni–Co–As–S from the bedded manganese ore deposits in the eastern part of Yamaguchi Prefecture; on the chemical compositions of gersdorffi te–cobaltite solid solution. Science Reports, Department of Geology, Kyushu University, Vol. 13, pp. 239-249.
Gübelin, E.J. & Koivula, J.I. (2005). Photoatlas of Inclusions in Gemstones. Volume 2. Opinio Publishers, Basel, Switzerland, 829 p., ISBN 3-03999-029-2.
Gervilla, F., Leblanc, M., Torres-Ruiz, J. & Fenoll Hachalí, P. (1996). Immiscibility between arsenide and sulfide melts: a mechanism for the concentration of noble metals. The Canadian Mineralogist, Vol. 34, Issue 3 (June), pp. 485-502. The Canadian Mineralogist Tables of Contents
Hem, S.R. & Makovicky, E. (2004).
The system Fe–Co–Ni–As–S. II. Phase relations in the (Fe,Co,Ni)As1.5S0.5 section at 650° and 500°C.
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The Canadian Mineralogist Tables of Contents
Hem, S.R., Makovicky, E. & Gervilla, F. (2001). Compositional trends in Fe, Co and Ni sulfarsenides and their crystal-chemical implications; results from the Arroyo de la Cueva deposits, Ronda Peridotite, southern Spain. The Canadian Mineralogist, Vol. 39, Issue 3 (June), pp. 831-853. The Canadian Mineralogist Tables of Contents
Höfelt, J.C. (2016). Personal communication.
Hyrsl, J. & Niedermayr, G. (2003). Geheimnisvolle Welt: Einschlüsse im Quarz | Magic World: Inclusions in Quartz. Bode Verlag GmbH, Haltern, Germany, 240 p. ISBN 3-92509481-4 (in German | English).
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Oen, I.S., Dunn, P.J. & Kieft, C. (1984). The nickel-arsenide assemblage from Franklin, New Jersey: description and interpretation. Neues Jahrbuch für Mineralogie, Abhandlungen, Vol. 150, No. 3, pp. 159-172.
Sokolov, P.B. & Henn, U. (1998). Gersdorffiteinschlüsse in Quarz aus dem Ural, Russland. Gemmologie: Zeitschrift der Deutschen Gemmologischen Gesellschaft, Vol. 47, No. 2, pp. 103-105 (in German).
Stalder, H.A. & Soom, M. (1990). Co-Ni-Arsensulfide in alpinen Mineral-Zerrklüften. Jahrbuch des Naturhistorischen Museums Bern, Vol. 10, pp. 81-92 (in German).
Wagner, T. & Lorenz, J. (2002). Mineralogy of complex Co–Ni–Bi vein mineralization, Bieber deposit, Spessart, Germany. Mineralogical Magazine, Vol. 66, Issue 3 (June), pp. 385-407. Mineralogical Magazine Tables of Contents
Legend: FoV: Field-of-View; DoF: Total focusing depth; DF: darkfield; Obl: oblique illumination (fiber optics); Pol: polarising filter before objective; Sh: shadowing; TM: transmitted illumination, UVL: long-wave ultra-violet radiation; UVS: short-wave ultra-violet radiation; X-Pol: crossed polarising filters; diff: diffused light