Cadmoindite (CdIn2S4) is a rare cadmium indium sulfide mineral discovered in Siberia around the vent of a high-temperature (450–600 °C) fumarole at the Kudriavy volcano, Iturup Island in the Kuril Islands.

It has also been reported from the Kateřina Coal Mine in Bohemia, Czech Republic.

[3] CdIn2S4 exhibits the spinel structure, which can be described by a cubic unit cell with 8 tetrahedrally coordinated and 16 tetrahedrally coordinated cation sites.

The distribution of Cd(II) and In(III) over the cation sites is difficult to elucidate from standard X-ray diffraction techniques because the two species are isoelectronic, but both Raman spectroscopy measurements on synthetic samples[4] and density functional theory simulations[5] indicate that about 20% of the tetrahedral sites are occupied by In(III) cations.

This article about a specific sulfide mineral is a stub.