Crystal is a type of hard substance that has special molecular arrangement. Crystals are highly transparent and have a geometrically regular shape. Some crystals are precious. For example, emerald and diamond while some commonly occur like ice crystals, salt, sugar crystals, etc. Crystal can be differentiated from glass by the fact that crystal contains lead which makes it heavier. Different chemicals present in crystals give them various colours. It also depends on how light is absorbed by the molecules of the solid.
What are Crystals?
