Pisces is a water sign so it is not surprising that their birthstone is the beautiful aquamarine, which literally translates from Latin to mean 'water of the sea'. The sun sign symbol of the Pisces features fish and according to ancient folklore, aquamarine is believed to be the treasure of the mermaids . Aquamarine is a stone of courage. Its calming energies reduce stress and quiet the mind. Aquamarine has an affinity with sensitive people. It can invoke tolerance of others and overcomes judgmentalism, giving support to those overwhelmed by responsibility