The Allende meteorite fell to the ground in Mexico in 1969. This cross-polarized light micrograph of a section through it, at a magnification of 200 times, shows that it is composed of small spherical mineral grains known as chondrules. This is typical of the most common group of meteorites, the chondrites or stony meteorites. The chondrules probably existed as independent particles in space before clumping together to form the meteorite.