CM Carbonaceous Chondrites are one of the most studied and widely collected groups of Carbonaceous Chondrite meteorites, known for their rich content of water-bearing minerals and organic compounds. The ‘CM’ designation comes from the Mighei meteorite, the type specimen of the group. Formed over 4.5 billion years ago, CM Chondrites have undergone significant aqueous alteration on their parent body, meaning they interacted extensively with water early in their history. This process has preserved important chemical signatures linked to the early solar system.

CM Carbonaceous Chondrites typically display a dark, fine-grained matrix with small chondrules that may be partially altered or less distinct. They contain very little metal but are rich in hydrated minerals such as clays, along with a wide range of organic compounds including amino acids. Their appearance is often matte and subdued, reflecting their altered and fragile nature. Many specimens are relatively soft compared to other meteorite types and can show signs of terrestrial weathering if not well preserved.

Studying CM Carbonaceous Chondrites provides key insight into the role of water and organic chemistry in the early solar system. They are particularly important for understanding how essential compounds for life may have been delivered to Earth. For collectors, CM Chondrites are highly desirable due to their scientific importance, recognisable characteristics, and connection to prebiotic chemistry. Each specimen represents a complex and information-rich piece of early solar system history.