In 1937 (Norsk geo!. tidsskrift. 17. 17-30) M. A. PEACOCK pub1ished an investigation on rosenbuschite, in which he showed, that this mineral has the chemical composition (Na, Ca, Mn)12 (Fe111, Ti, Zr)4 (Si8O82)F4. The unit cell is triclinic. The relation to wollastonite, suggested by Brøgger, could not be confirmed. Peacock believes that the mineral belongs to the wohlerite group, apparently without knowing that the wohlerite group already had been investigated.