Norilskit wird mit folgenden Werten angegeben. Hieraus errechnet sich eine Dichte von 12.995 g/cm³. Dies erscheint mir etwas hoch da weder Blei noch Silber noch Palladium eine derart hohe Dichte aufweisen. Hat zufällig jemand den vollen Artikel.
A Vymazalova, F Laufek, S F Sluzhenikin, C J Stanley. Norilskite (Pd,Ag)7Pb4, a new mineral from Noril'sk-Talnakh deposit, Russia. Mineralogical Magazine 81: 541-551.
Norilskite, (Pd,Ag)7Pb4 is a new platinum-group mineral discovered in the Mayak mine of the Talnakh deposit, Russia. It forms anhedral grains in aggregates (up to about 400 μm) with polarite, zvyagintsevite, Pd-rich tetra-auricupride, Pd-Pt bearing auricupride, Ag-Au alloys, (Pb,As,Sb) bearing atokite, mayakite, Bi-Pb rich kotulskite and sperrylite in pentlandite, cubanite and talnakhite. Norilskite is brittle, has a metallic lustre and a grey streak. Values of VHN20 fall between 296 and 342 kg/mm2, with a mean value of 310 kg/mm2, corresponding to a Mohs hardness of approximately 4. In plane-polarized light, norilskite is orange-brownish pink, has moderate to strong bireflectance, orange-pink to greyish-pink pleochroism, and strong anisotropy; it exhibits no internal reflections. Reflectance values of norilskite in air (Ro, Re’ in %) are: 51.1, 48.8 at 470nm, 56.8, 52.2 at 546nm, 59.9, 53.5 at 589nm and 64.7, 55.5 at 650nm. Sixteen electron-microprobe analyses of natural norilskite gave an average composition: Pd 44.33, Ag 2.68, Bi 0.33, and Pb 52.34, total 99.68 wt.%, corresponding to the empirical formula (Pd6.56Ag0.39)Σ6.95(Pb3.97Bi0.03)Σ4.00 based on 4 Pb+Bi atoms; the average of eight analyses on synthetic norilskite is: Pd 42.95, Ag 3.87, and Pb 53.51, total 100.33 wt.%, corresponding to (Pd6.25Ag0.56)Σ6.81Pb4.00. The mineral is trigonal, space group P3121, with a 8.9656(4), c 17.2801(8) Å, V 1202.92(9) Å3 and Z = 6. The crystal structure was solved and refined from the powder X-ray-diffraction data of synthetic (Pd,Ag)7Pb4. Norilskite crystallizes in the Ni13Ga3Ge6 structure type, related to nickeline. The strongest lines in the X ray powder diffraction pattern of synthetic norilskite [d in Å (I) (hkl) ] are: 3.2201(29)(023,203), 2.3130(91)(026,206), 2.2414(100)(220), 1.6098(28)(046,406), 1.3076(38)(246,462), 1.2942(18)(600), 1.2115(37)(22.12,12.13), 0.9626(44)(06.12,60.12). The mineral is named for the locality, the Noril`sk district in Russia.
Viele Grüße
Stefan
Thema: Norilskit (Gelesen 2202 mal)
Mineralienatlas - Fossilienatlas - Info-Center
