The rarest and, in general, the least primitive of the three main classes of chondrite meteorite. They are much less oxidized than the ordinary chondrites. Iron in the metallic state constitutes 15–25% of their mass, and the principal silicate is a nearly iron-free pyroxene known as enstatite. The enstatite chondrites are divided into two subgroups according to whether the ratio of iron to silicon in the meteorite is high (the EH group) or low (the EL group). The EH and EL groups are probably derived from separate parent bodies. Most enstatite chondrites are breccias. They are chemically similar to the aubrites (enstatite achondrites) and may have originated from the same parent bodies.