Kitagohaite, Pt.sub.7./sub.Cu, a new mineral from the Lubero region, North Kivu, Democratic Republic of the Congo

0432914 - GLÚ 2015 RIV GB eng J - Článek v odborném periodiku
Cabral, A. R. - Skála, Roman - Vymazalová, A. - Kallistová, Anna - Lehmann, B. - Jedwab, J. - Sidorinová, T.
Kitagohaite, Pt₇Cu, a new mineral from the Lubero region, North Kivu, Democratic Republic of the Congo.
Mineralogical Magazine. Roč. 78, č. 3 (2014), s. 739-745. ISSN 0026-461X. E-ISSN 1471-8022
Institucionální podpora: RVO:67985831
Klíčová slova: kitagohaite * Pt₇Cu * Lubero * North Kivu * Democratic Republic of the Congo
Kód oboru RIV: DB - Geologie a mineralogie
Impakt faktor: 2.026, rok: 2014

Kitagohaite, ideally Pt₇Cu, is a new mineral from the Lubero region of North Kivu, Democratic Republic of the Congo. The mineral occurs as alluvial grains that were recovered together with other Pt-rich intermetallic compounds and Au. Kitagohaite is opaque, greyish white and malleable and has a metallic lustre and a grey streak. In reflected light, kitagohaite is white and isotropic. The crystal structure of kitagohaite is cubic, space group Fm3¯m, of the Ca₇Ge type, with a = 7.7891(3) A ˚ , V = 472.57(5) A ˚ 3 and Z = 4. The strongest diffraction lines [d in A ˚ (I)(hkl)] are: 2.246 (100)(222), 1.948(8)(004), 1.377 (77)(044), 1.174(27)(622), 1.123 (31)(444) and 0.893 (13)(662). The Vickers hardness is 217 kg mm 2 (VHN100), which is equivalent to a Mohs hardness of 3 and the calculated density is 19.958(2) g cm 3. Electron-microprobe analyses gave a mean value (n = 13) of 95.49 wt.% Pt and 4.78 wt.%Cu, which corresponds to Pt6.93Cu1.07 on the basis of eight atoms. The new mineral is named for the Kitagoha river, in the Lubero region.
Trvalý link: http://hdl.handle.net/11104/0237233