asteroid spectral type; siliceous (stony) composition and high density
433 Eros, an example of an S-type asteroid
S-type (stony-type or siliceous-type) asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second-most common after the carbonaceous C-type.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).