Their surface composition is similar to carbonaceous chondrite meteorites. The Vestian asteroids and HED meteorites are examples. It has also been identified as presolar grains in carbonaceous chondrite meteorites. Carbonaceous chondrite meteorites contain kerogen-like components. Most meteorites are stony meteorites, classed as chondrites and achondrites. These features were caused by the collision of large meteorites or comets with the Earth. Eskolaite is also a rare component of chondrite meteorites. It also occurs in igneous rocks and in meteorites. Bitumen is similar to the organic matter in carbonaceous meteorites. "Fossil" meteorites are sometimes discovered by geologists. Peridot crystals have been collected from some pallasite meteorites. Andesite is different from the rocks found in meteorites that have come from Mars. Fire occurs naturally as a result of volcanic activity, meteorites, and lightning strikes. The terrestrial alteration of meteorites is called weathering. There are also instances of magnetite with origins in space coming from meteorites.