Myanmar produces precious stones such as rubies, sapphires, pearls, and jade. Rubies are the biggest earner; 90% of the world's rubies come from the country, whose red stones are prized for their purity and hue. Thailand buys the majority of the country's gems. Myanmar's "Valley of Rubies", the mountainous Mogok area,  north of Mandalay, is noted for its rare pigeon's blood rubies and blue sapphires.