What minerals are found on S-class asteroids?

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Illustration showing a massive asteroid above a city map with a dinosaur silhouette for scale, highlighting the asteroid's size compared to major urban areas. — Asteroid This rock would take out more than just a *T. rex*.

S-class asteroids are characterized by moderate albedos and are known to contain significant amounts of silicates and metals. Specifically, their surfaces are composed of mixtures of the following minerals:1

Olivine21
Pyroxene21
Metallic iron2

While these minerals are also found in ordinary chondrites, the observed spectral differences between S-class asteroids and these meteorites were historically a subject of scientific debate. This discrepancy was eventually resolved by the discovery of space weathering—a process involving impacts and solar radiation that alters the surface properties of asteroids over time, making them appear distinct from their internal composition.2