Yes, it is true that the Moon is predominantly composed of rock. The Moon is a rocky astronomical body that orbits Earth and is Earth's only natural satellite. Its surface is covered in various types of rocks and regolith, which is a layer of fragmented material that covers solid rock.
The primary rock type found on the Moon is called basalt, which is a volcanic rock formed from solidified lava. Basalt makes up the dark, flat regions on the Moon's surface known as maria. These areas were formed by ancient volcanic activity on the Moon.
In addition to basalt, the Moon's crust also contains other types of rocks, including anorthosite, which is a light-colored rock composed mainly of a mineral called plagioclase feldspar. The highlands of the Moon, which are the bright, rugged regions, are primarily composed of anorthosite.
The Moon's interior is also believed to be rocky. It is thought to have a solid, rocky core surrounded by a partially molten layer known as the lunar mantle. The exact composition and structure of the Moon's interior are still subjects of ongoing scientific research and exploration.
Overall, while the Moon may contain some small amounts of other elements and compounds, its composition is predominantly rocky, with basalt and anorthosite being the primary types of rocks found on its surface.