Today we learnt about crystallization. It is used to separate a dissolved solid from a solution. You need a saturated solution (it's not the same as concentrated!) to carry out crystallization.

What is a saturated solution? It contains the maximum amount of solute dissolved in a given volume of solvent at a particular temperature. However, a concentrated solution is a solution that contains lots of solute dissolved in it.

One way to do crystallization is 'seeding'. A small crystal from your solute is suspended from  a thread in a saturated solution. The crystals will then grow in size as the solute crystallizes out from the saturated solution which is evaporating slowly.