A manganoan hedenbergite Hd68Jo32 from the Nakatatsu mine, Fukui Prefecture, Japan, is described. The mineral occurs in the hedenbergite skarn zone. Lattice constants are: a=9.868(6)Å, b=9.047(5)Å, c=5.255(3)Å and β=104.84(6)°. The space group is C2⁄c and Z=4. The crystal structure of the mineral was refined to an R factor of 3.8% for 505 observed reflections. The structure is very similar to that of hedenbergite.
