CONICET | Buscador de Institutos y Recursos Humanos

Kinoite was found as thin veinlets intergrown with apophyllite-(KF) cutting skarn masses enclosed in marble at Level 535 of the Cantera Sur, Malagueño (Córdoba). This copper silicate occurs as fracture fillings or groups of bright blue crystals up to 0.4 mm long, with vitreous luster. They are strongly pleochroic, with Z = deep blue, X = pale greenish blue. Electron microprobe analyses (n = 7) gave (wt.%) SiO2 37.27, Al2O3 0.11, FeO 0.12, MgO 0.02 CuO 32.65, ZnO 0.09, CaO 23.39, H2O (calc.) 7.47, total 101.03. The empirical formula is (Ca2.01Fe0.01)S2.02Cu1.98(Si2.99Al0.01)S3.00O10·2H2O. Unit cell dimensions (X-ray powder diffraction) are a = 6.984(1), b = 12.895(3), c = 5.654(1) Å, b = 96.18(2)º, V = 506.2(2) Å3, in very close agreement with type kinoite. Veinlets are composed of an intermediate member of the diopside-hedenbergite series (En26Fs22), titanite, perthitic potassic feldspar (Or95,7Ab4,2An0,01), with scarce barite. Kinoite is always found inside apophyllite-(KF). Tenorite was found in the marble, but it is not part of the kinoite-bearing assemblage. Kinoite+apophyllite-(KF) veinlets are restricted to the endoskarn, and are never found crosscutting marble. Therefore, the origin of this association must be related to the process of skarn replacement.