Summary: Vincentite, a new palladium mineral containing As, Sb, and Te, has been discovered in platinum-gold concentrates from the Riam Kanan River, SE. Borneo. It occurs as small grains (up to 40 µm) in iron-bearing platinum. In reflected light, vincentite is light brownish-grey and in some sections weakly anisotropic. Reflectance at 470, 546, 589, and 650 nm is 46·3–47·5, 49·2–52·8, 51·7–53·9, and 54·9–56·0, respectively. VHN₁₅ = 494. Electron probe analysis has been performed on two grains, the compositions of which are (Pd_5·32Pt_0·68) (As_0·90Sb_0·48Te_0·65) and (Pd_5·17Pt_0·83) (As_0·89Sb_0·70Te_0·45) or, simplified, (Pd,Pt)₃(As,Sb,Te). This is distinctly different from both arsenopalladinite, Pd₅(As,Sb)₂ with As > Sb as defined by Clark (1974), and mertieite, Pd₅(Sb,As)₂.

The following lines have been observed in the powder pattern: 4·180, 3·950, 3·240, 2·750, 1·997, 1·749, 0·944. This cannot be matched by the patterns of arsenopalladinite, mertieite, isomertieite, stibiopalladinite, atheneïte, or synthetic Pd₃As.

The name is in honour of Prof. E. A. Vincent, of Oxford.