Turquoise is an ornamental stone which has been prized for centuries due to its beautiful colour. The word turquoise is derived from an old French word for Turkish, as the mineral was first brought to Europe from Turkey, mined in the historical 16th century Khorasan Province of Persia. In Iranian architecture, the blue turquoise was used to cover the domes of the Iranian palaces. Its intense blue colour was a symbol of Heaven on Earth and is said to have a calming effect and used to treat panic attacks.
Turquoise is the colour and gemstone of Sagittarius and since 1873 has been known as Robin Egg Blue.