Stony meteorite

Meteorites are natural objects originating in outer space that fall to Earth and survived with the impact of Earth's surface. The Earth is about 4.6 billion years old, but the oldest known rocks that originated from plate tectonic are about 3.8 billion of age. Therefore, the study of meteorite is an efficient method to know the Earth's early formation and evolution. Meteorites can generally classify into three categories by its composition: stony meteorite, iron meteorite, stony-iron meteorite, and stony meteorite can be further divided into Chondrite and Achondrite by composition. Chondrite is named because of regular millimeter size of outlined chondrules and different from general igneous rocks in interlock structure. The original dust cloud from the solar nebula formed droplets as a direct result of high temperature, and condensed without differentiation to form Chondrite. The composition of Chondrite was most similar to the primitive solar system, namely the most important meteorite to realize the evolution of early solar system. Achondrite is stony meteorites that had undergone the differentiation. Its chemical composition was different from the original components. It lost a large amount of metal materials and possessed no outlined chondrules. The chemical composition and mineral structure were similar to the Earth rocks.