The hexagonal ferrites, of current interest because of their high‐frequency properties, are being studied by single‐crystal x‐ray methods. A new rhombohedral member of the group, ideally Ba4Zn2Fe52O84, has been identified. The centrosymmetric space group is R3̄m; referred to hexagonal axes, c=153.85 Å, a=5.88 Å, and there are 66 anion layers in the c‐axis repeat period. The stacking sequence was established by (00.l) structure factor and one‐dimensional electron density calculations. The new structure forms a series of mixed‐layer compounds with three of the original phases. All of the hexagonal ferrites are thus characterized by two series, each of which features the c‐axis interlayering of two discrete structural units. Stacking relations within and between the two series are discussed, along with implications for new structures and series.