Inside the Moon contain a hard outer crust, rigid outer mantle and semi rigid inner mantle and a core inside the moon that is cooler than interior of Earth. As moon is very small it gives out it's heat quickly. The ratio of surface to volume in moon is also very small compare to Earth. In forming of moon and Earth, the moon cooled much more than earth.

                               Crust:                            

Surface of moon is dry, dusty and rocky. The thickness of rock crust is about 37 miles (60 km) on the side face to Earth andit is in the opposite side. This thickness is about 62 miles (100 km)

NASA'S Apollo mission says the formation of moon occurred about 4.3 billion years ago (about 60 million years after formation of Earth).

The rocks in moon and Earth are similar but Moon's rock have more aluminum and titanium according to NASA'S analysis.

There are minerals Armalcolite (named for three astronauts on NASA'S Apoll 11: Neil ARM strong , BUZZ Aldrin and Michael Collins), Tranquilities the Earth, but some of these minerals been found on the Earth.

           Rigid lithosphere mantle:            

This is a rock layer which is not that much hot to flow and it's thickness is about 620 miles (1000 km).

                  Non-rigid mantle:                  

This is a asthenospheric layer and only the deepest parts of that are hot enough to flow and it's rigidity is less than lithosphere but can transmit seismic waves.

                              Core:                            

This is non-fluid and probably made of iron-rich rock which is only 2 to 4 percent of total mass of Moon and it's diameter may be is around 225 miles on 360 km.

The magnetic field of moon is one ten-millionth of the Earth's magnetic field and this small core can not creat much magnetic field. Therefore a compass can not work on the moon but as there is no atmosphere, sky always is dark and we can navigate by looking at stars.