RECENTLY Huffman1, Manning2,3 and Dorschner4 have suggested that the diffuse interstellar bands may be caused by transitions in 3d ions situated in the tetrahedral and octahedral sites in the lattices of interstellar silicate grains. Manning3 has proposed that the grains might consist of iron-bearing garnets of the almandine and andradite type. In particular, the 4430 A band may be caused by the field-independent transition 6A1(S)→4A1,4E(G) in the Fe3+ ions of andradite.