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Orishchinite is a new terrestrial phosphide discovered in pyrometamorphic rocks of the Daba-Siwaqa combustion complex in West Jordan. The mineral occurs as an accessory phase in the fused clinopyroxene-plagioclase rock (paralava) texturally resembling gabbro-dolerite. Orishchinite forms resorbed equant grains up to 0.2 mm outrimmed with 0.1–0.2 thick zones of substituting murashkoite, FeP. Chemical composition (electron microprobe, wt%): Ni 38.49, Fe 22.38, Co 0.47, Mo 18.80, P 19.46, Total 99.60, corresponding to the empirical formula (Ni1.04Fe0.64Mo0.31Co0.01)Σ2.00P on the basis of 3 apfu. The simplified formula is (Ni,Fe,Mo)2P and the ideal one is Ni2P. Macroscopically, orishchinite grains have yellowish-white colour with metallic lustre. The mineral is brittle. In reflected light, orishchinite is yellowish-white and non-pleochroic. It is very weakly anisotropic (ΔR589 = 1.3%). Reflectance values for the wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are [Rmax/Rmin (%), λ (nm)]: 48.1/47.5, 470; 50.6/49.4, 546; 52.1/50.8, 589; 54.4/52.9.1, 650. The crystal structure was solved and refined to R1 = 0.016 based on 224 unique observed [I ≥ 2σ(I)] reflections. Orishchinite is orthorhombic, space group Pnma, a 5.8020(7), b 3.5933(4), c 6.7558(8) Å, V 140.85(3) Å3, Z = 4, Dx = 7.695 g cm-3. The strongest lines of the powder X-ray diffraction pattern [(d, Å) (I, %) (hkl)] are: 2.265(100)(112), 2.201(16)(202), 2.142(55)(211), 2.100(35)(103), 1.909(21)(013), 1.811(19)(113), 1.796(31)(020). Orishchinite is dimorphous with transjordanite (hexagonal Ni2P) and can be considered the Ni-dominant analogue of allabogdanite. [ABSTRACT FROM AUTHOR]