MS15-P05 Structural diversity of terrestrial phosphides related to Fe-Ni-P system Maria Krzhizhanovskaya (Department of Crystallography, Institute of Earth Sciences, Saint-Petersburg State University, St. Petersburg, Russia) Sergey Britvin (Department of Crystallography, Institute of Earth Sciences, Saint-Petersburg State University, St. Petersburg, Russia) Michail Murashko (Department of Crystallography, Institute of Earth Sciences, Saint-Petersburg State University, St. Petersburg, Russia) Yevgeny Vapnik (Ben-Gurion University of the Negev , Beer-Sheva, Israel) Andrey Zolotarev (Department of Crystallography, Institute of Earth Sciences, Saint-Petersburg State University, St. Petersburg, Russia)email: krzhizhanovskaya@mail.ruThe recent findings of terrestrial phosphides related to Fe-Ni-P triangle (Table 1) substantially expand our knowledge on this important cosmochemical system. We herein provide comparative crystal chemical characteristics of terrestrial phosphides vs. their counterparts of space origin. Crystal structures of some of the listed minerals are studied by both single crystal and powder X-ray diffraction. Special attention has been paid to the distribution of iron and nickel in their structures.  The possibility of X-ray diffraction approach, involving anomalous scattering of CoKα-radiation at the Fe-K edge, is discussed.
 
Table 1. Natural phosphides in the Fe-Ni-P system
 
Mineral Formula Structural type
Negevite NiP2 Pyrite
Zuktamrurite FeP2 Marcasite
Murashkoite FeP FeP
Halamishite Ni5P4 Ni5P4
Transjordanite Ni2P Fe2P
Barringerite Fe2P Fe2P
Allabogdanite (Fe,Ni)2P Co2Si
Nickelphosphide (Ni,Fe)3P Ni3P
Schreibersite Fe3P Ni3P
Melliniite (Ni,Fe)4P Cr4Si
 
 
* The names of new phosphide minerals are highlighted by italic.
 
This study was carried out under financial support of Russian Scientific Foundation, grant no. 18-17-00079. The authors thank the Center for X-ray Diffraction Studies and Geomodel Center of Saint-Petersburg State University for instrumental and computational support.
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Keywords: phosphides, crystal structure, mineral