Diogenites are achondrites from the HED group of meteorites, originating from the asteroid Vesta. They were formed by magmatic activity in the deeper layers of its crust and mantle, from where they were ejected into space by the ancient impact of another cosmic body.
The main mineral is orthopyroxene, often with admixtures of olivine and plagioclase. Their coarse-grained structure reveals the conditions on Vesta billion years ago.