Lapis lazuli is a metamorphic rock that's been prized as a gemstone for thousands of years. Most of the world's finest material comes from north east Afghanistan. The province of Badakhshan is home to the oldest lapis mines in the world.
Although often referred to as a mineral, lapis lazuli is a rock. This is because it's made up of several different minerals. The mineral lazurite is largely responsible for the stone's blue colour.