Anorthosite

Anorthosite

This white rock is composed almost entirely of crystals of one mineral, feldspar. Rocks like this make up much of the Highlands of the Moon, where feldspar produces the light color. Shortly after material gathered together to form the Moon, the outer Moon melted. As the melt cooled, feldspar crystals formed and floated (like ice cubes in water) upward to form the Moon’s crust. At first the feldspar crystals were pale gray or colorless. Then meteorites collided with the Moon and broke up its crust into fragments, and shocked and shattered the feldspar crystals so they are now white. The rusty, red grains on the sample are iron metal from the Moon which has reacted with water and oxygen on Earth.

The chip in this disk, which weighs about 1/2 gram, was removed from a 1185 gram (2.6 lb.) rock, number 66095. The Apollo 16 astronauts found the rock loose on the surface at the base for Stone Mountain in the Des Cartes region of the light colored highlands near the center of the Moon.

This white rock is composed almost entirely of crystals of one mineral, feldspar. Rocks like this make up much of the Highlands of the Moon, where feldspar produces the light color. Shortly after material gathered together to form the Moon, the outer Moon melted. As the melt cooled, feldspar crystals formed and floated (like ice cubes in water) upward to form the Moon’s crust. At first the feldspar crystals were pale gray or colorless. Then meteorites collided with the Moon and broke up its crust into fragments, and shocked and shattered the feldspar crystals so they are now white. The rusty, red grains on the sample are iron metal from the Moon which has reacted with water and oxygen on Earth.

The chip in this disk, which weighs about 1/2 gram, was removed from a 1185 gram (2.6 lb.) rock, number 66095. The Apollo 16 astronauts found the rock loose on the surface at the base for Stone Mountain in the Des Cartes region of the light colored highlands near the center of the Moon.