A new quaternary rare-earth sulfide has been isolated and identified. Crystals of La 6 MgGe 2 S 14 , as well as of the previously identified La 6 MgSi 2 S 14 have been grown from a mixed binaryhalide eutectic flux. They both crystallize in the hexagonal space group C 6 6 -P6 3 , with Z" "1. The crystal structures of these compounds have been determined by single-crystal X-ray diffraction techniques. Crystal data are La 6 MgGe 2 S 14 -a" "10.367(1) A s , c" "5.814(1) A s (T" "298 K), V" "541.09(8) A s 3 , R w (F 2 )" "0.050, R 1 (on F)" "0.018; La 6 MgSi 2 S 14 -a" "10.363(2) A s , c" "5.742(1) A s (T" "298 K), V" "534.1(2) A s 3 , R w (F 2 )" "0.058, and R 1 (on F )" "0.022. Structurally, these compounds belong to the Ln 6 M 2 M 2 S 14 family (Ln" "rare-earth, M" "first-row transition metal or main-group metal, M" "main-group metal). Their structures are characterized by one-dimensional chains of MS 6 face-sharing octahedra running parallel to the 6 3 axis, surrounded by isolated MS 4 tetrahedra aligned along the three-fold axes.