Rock

Rock is a material representing a solid aggregate of minerals and mineraloids.

Contains
The composition of rock depends on the minerals that it contains, but include
 * silica
 * aluminium
 * iron
 * potassium
 * sodium
 * calcium

Found Inside
It is found in the crusts of barren planets, visitor planets, moons, asteroids, inside planetary cores, and on their surfaces inside mountains (and their inhabited counterparts ancient mountains), caves and fallen meteorites.

Inside dragons are pyroliths, which are also made of rock.

Sometimes mausoleums and graves are made of rock.