Stone, Rock or Crystal?
A rock is an aggregate of one or more minerals. A rock may also include organic remains
(i.e. petrified matter)
A stone is a small piece of rock.
A pebble is a small piece of naturally rounded stone.
A crystal is a solid rock formation in which the atoms, molecules and ions are packed in an ordered, repeating pattern extending in all three spatial directions. The etymology of the word “crystal” is Greek from “krystallos” meaning clear as ice as crystal was originally though to be a solid form of water.
All crystals are stones but not all stones are crystals