Seven Allende meteorite fragments. The Allende meteorite fell close to the village of Pueblito de Allende, Mexico in 1969. The meteorite was formed during the early formation of the Solar System and is classed as a stony meteorite. Most Allende fragments have a black, shiny crust created as the stone descended at great speed through the atmosphere. This caused the exterior of the stone to become very hot, melting it, and forming a glassy fusion crust. The interior of the fragments shows a dark matrix embedded throughout with millimetre-sized, lighter-coloured chondrules, tiny stony spherules found only in meteorites and not in Earth rock (thus it is a chondritic meteorite). Also seen are calcium-aluminium-rich inclusions (CAIs). The Allende meteorite also contains cosmogenic nuclides (or cosmogenic isotopes) which are rare nuclides (isotopes) created when high-energy cosmic rays interact with atoms in the meteorite.