Kitagohaite, Pt₇Cu, a new mineral from the Lubero region, North Kivu, Democratic Republic of the Congo Available to Purchase

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 Fm3İm, of the Ca₇Ge type, with a = 7.7891(3) Å, V = 472.57(5) ų and Z = 4. The strongest diffraction lines [d in Å(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 3½ 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 Pt_6.93Cu_1.07 on the basis of eight atoms. The new mineral is named for the Kitagoha river, in the Lubero region.