A type of asteroid, relatively common in the inner main asteroid belt, having a moderate albedo (0.10–0.28), a reddish spectrum at wavelengths shorter than 0.7 μ‎m, and moderate to non-existent absorption features at longer wavelengths. The proportion of S-type asteroids decreases outwards through the main belt. The S is for silicaceous, since their composition is thought to include silicate minerals such as olivine and pyroxene. They are thought to be the parent bodies of the ordinary chondrite meteorites. Examples include (15) Eunomia, diameter 232 km, and (29) Amphitrite, diameter 190 km.