This new antimonate was found in the cinnabar-bearing gravel of Tripuhy, Minas Geraes, Brazil. The minerals associated with it in the gravel, including the two new titano-antimonates lewisite and derbylite, have already been described in this Magazine (Vol. XI. No. 50, p. 80, and No. 52, p. 176). The original source of the lewisite and derbylite has been proved to be the muscovite-schists accompanying itabirite in the neighbourhood of Tripuhy, From these schists, doubtless, is also derived the tripuhyite, although as yet this new mineral has only been found in fragments loose in tbe gravel, and not intergrown with fragments of the muscovite-schists as is often the ease with both lewisite and derbylite.