Chemistry is complicated and it is not always very intuitive but it surrounds you and it is full of beauty, have a look below:
Minerals
A mineral, aluminium oxide with chromium (Al2O3:Cr); also known as ruby.
Reactions
Fulminating gold is a compound containing ammonia, chlorine, and gold which is highly explosive and shock sensitive. The purple smoke it emits when it explodes is caused by gold nanoparticles!
Materials
Bismuth is an element of the periodic table. Its crystals are square and reflect rainbow colours. The square-faces are because of the rhombohedral lattice system. The rainbow is because of varying layers of oxides on the surface.