CHondritic

Chondritic is an adjective used in meteoritics and planetary science to describe material derived from chondrites, a class of stony meteorites that have not undergone significant melting or differentiation. Chondritic meteorites are among the most primitive solar system materials and preserve records of the early solar nebula.

Chondrites are characterized by chondrules, small round silicate grains formed as molten droplets in the early solar system. Chondrules are embedded in a fine-grained matrix and, together with mineral grains and sometimes metal sulfides, constitute the bulk of the meteorite's texture. The chondritic assemblage indicates formation under relatively low degrees of thermal processing.

Modern classification groups chondritic meteorites into ordinary, carbonaceous, and enstatite chondrites, with several subtypes (for example H, L, LL ordinary; CI, CM, CO, CV, CK, CR carbonaceous; EH, EL enstatite). CI chondrites are among the most chemically primitive and are used as a reference for solar composition.

Chondritic material is prized in cosmochemistry because it preserves the earliest records of the solar system, including isotopic ages and volatile abundances. Isotopic systems such as Al-26-Mg-26 and Pb-Pb are used to date chondritic components to around 4.56 billion years. The study of chondrites informs models of planetesimal formation, water delivery, and the early evolution of planets.

Terminology: the term chondritic is sometimes used to describe the bulk composition of planetary bodies that closely approximates that of chondritic meteorites, and to distinguish materials that are not heavily differentiated from those that have undergone melting and segregation.