Black Cu₂Bi₂S₃(AlCl₄)₂ and orange Ag₂Bi₂S₃(AlCl₄)₂ were synthesized by solvent-free reaction (polycrystalline powders) as well as in Lewis-acidic ionic liquids (crystals) at temperatures of 200 ° C or lower. X-ray diffraction on single-crystals of Cu₂Bi₂S₃(AlCl₄)₂ revealed two centrosymmetric polytypes: a rhombohedral one, space group R3¯c [a = 658.02(3) pm, c = 6794.3(3) pm], with six formula units in the unit cell (6R polytype), and a hexagonal one, space group P6₃/m [a = 658.71(6) pm, c = 2265.5(3) pm], with two formula units (2H polytype). Ag₂Bi₂S₃(AlCl₄)₂ is homeotypic and crystallizes in the acentric hexagonal space group P6 2c with [a = 691.65(3) pm, c = 2207.86(9) pm, and two formula units per unit cell (2H′ polytype). All structures consist of ²_∞[(M⁺)₂Bi₂S₃] layers (M = Cu, Ag) separated bydouble layers of AlCl₄^- tetrahedra and differ mainly in their stacking sequences and the orientation of the AlCl₄^- groups. The sulfidometalate layer is a honeycomb-like network with M⁺ and S^2- ions in plane, whereas pairs of Bi³⁺ cations occupy positions above and below the plane. The analysis of chemical bonding reveals strong covalent twocenter two-electron bonds in the five-atomic bipyramidal Bi₂S₃ unit (D_3h symmetry) and covalent bonding with much higher ionic component to the coin metal cations. The DFT-optimized shape of an isolated hypothetical Bi₂S₃ molecule differs only marginally from that in the layer. Hence, the compounds might be interpreted as Bi₂S₃ molecules embedded in MAlCl₄ salts. Optical bandgaps of 1.6 eV (M = Cu) and 2.2 eV (M = Ag) were deduced from diffuse reflectance measurements. DFT-based quantum chemical calculations indicate direct bandgaps of the same magnitude.