The light-colored areas on the Moon are called the highlands. These areas represent the earliest crust on the Moon and are composed of a type of rock called anorthosite, which is dominated by the white mineral anorthite or plagioclase. The highlands were shattered and deformed by impact cratering, which pushed some of the crust into mountain-high impact crater rims or ejected it across the surface of the Moon. In contrast, the dark areas on the Moon are called maria, which is the Italian and Latin word for "seas". These areas are young plains composed of basalt that flowed in and flooded the area created by a huge impact with an asteroid or comet. The maria cover about 15% of the Moons crust and have a higher metal content than surrounding lunar rock, giving them a blue tinge.