Model eclipse spectra of possible low-albedo surface types from R. Hu et al. (2012; using the surface model and updated albedo profiles of B. P. Coy et al. 2024) in units of brightness temperature, ignoring the opposition surge effect. High brightness temperatures at low wavelengths are due to the contribution from reflected light. The Bond albedo of these surfaces is 0.13 for metal-rich, 0.20 for Fe-oxidized, 0.24 for basaltic, and 0.49 for ultramafic. For comparison, we derive A_eff = 0.2 ± 0.1 from the prayer-bead eclipse spectrum. Black points represent our prayer-bead eclipse spectrum, whereas gray points show simulated observations of 10 eclipses with MIRI LRS using PandExo (N. E. Batalha et al. 2017), assuming an ultramafic surface.