The Moon has a rocky and metallic nucleus, nothing unusual. Layers and layers of rock. Now the rocks of the Moon are different in composition than the rocks of the Earth.
For a less entertaining, but more reality-based response than CSIFREAK's answer, try this: csep10.phys.utk.edu/astr161/lect/.
The core of the Moon is a type of anti electro magnetic material like (anti gravity) but the outer layer of the moon is attracted to the Earth electro magnetic field, because gravity works only on Inner Space. In Outer Space it is the electro magnetic field that kept the moon orbit around the Earth. The core of the moon is part of God design, to prevent the moon from colliding to Earth. It's core can only reach an area of Earth electro magnetic field, which God intend it to be. In short the Moon will only move away from the Earth'' because of the impact from meteors that continue to take away part of the surface material which is attracted to Earth electro magnetic fields. At the same time it can only move away very little, because the Moon is deep inside the Earth electro magnetic field to prevent it from moving away. For this reason the surface layer of the Moon has to very strong to sustain a hit of giant meteors. Although gravity is widely considered to held the position of every planets that orbit around the Sun, and the reason the Moon orbit around the Earth. Electro magnetic force is the dominant foundation of the Universe. Even to every breath we take, or every move we make, this too is associated with electro magnetic force in the brain of every living body.
