1. Turquoise is formed when water enters an iron-rich limonite or sandstone that contains copper, aluminum and other minerals, gathering those minerals together. It takes millions of years and the right conditions for turquoise to be formed. The presence of copper gives the blue, and the presence of aluminum adds a greenish hue to the stone.
2. Turquoise is known for its intense blue-green colour. The finest and rarest colour is an intense blue that is uniform throughout the stone such as the beautiful stones to the right, sourced from the Sleeping Beauty mines in Arizona, USA. You might assume that the name of the stone comes from it's colour, but it actually from the French word for Turkey since it was thought that the mineral originated there. The colour is named after the stone!
3. Turquoise is a relatively soft stone with a Mohs rating of between 5 and 6. Make sure that you handle it carefully, ideally storing it separately from other harder gemstones.
4. Turquoise isn't just one of December's birthstone, it's also important in Tibetan and Nepalese cultures. It is known as the 'Sky Stone' and has been revered by people in the Himalayas for thousands of years due to the belief that it came from the heavens. It is believed to bring protection and so children in Tibet are gifted turquoise gemstones to keep them safe on their journey through life.