Bortnikovite, a new mineral species that is an intermetallic compound of Pd, Cu, and Zn with the simplified formula Pd
4Cu
3Zn has been detected at the unique Konder placer deposit in the Ayan-Maya district, Khabarovsk krai. The primary source of
this placer is a concentrically zoned alkaline ultramafic massif. The X-ray diffraction pattern is indexed on the assumption
of a tetragonal unit cell:
a = 6.00 ± 0.02 Å and
c = 8.50 ± 0.03 Å,
V = 306 ± 0.01 Å
3,
Z = 3, probable space group
P4/
mmm. The calculated density is 11.16 g/cm
3; the mean microhardness VHN is 368 kg/mm
2. In reflected light, the new mineral is white with a slight grayish beige tint; bireflectance, anisotropy, and internal reflections
are not observed. The reflectance spectrum belongs to the concave group of the anomalous type. The measured values of reflectance
are as follows: 56.9 (470 nm), 61.7 (546 nm), 63.4 (589 nm), and 65.4% (650 nm). The new mineral is intergrown with isoferroplatinum,
titanite, perovskite, V-bearing magnetite, bornite, and chlorite. The origin of bortnikovite is related to the effect of alkaline
fluid on ultramafic rocks. The new mineral is named in honor of Professor Nikolai Stefanovich Bortnikov, a prominent mineralogist
and researcher of ore deposits and a corresponding member of the Russian Academy of Sciences. Bortnikovite is the first platinum
group mineral that contains Zn as a major mineralforming element.
Original Russian Text © A.G. Mochalov, M.D. Tolkachev, Yu.S. Polekhovsky, E.M. Goryacheva, 2007, published in Geologiya Rudnykh
Mestorozhdenii, 2007, Vol. 49, No. 4, pp. 357–366.
Considered by the Commission on New Minerals and Mineral Names, Russian Mineralogical Society, May 23, 2006. Approved by the
Commission on New Minerals and Mineral Names, International Mineralogical Association, August 31, 2006 (proposal no. 2006-027.)