Lapis Lazuli is a deep blue semiprecious stone that has been prized since antiquity for its intense colour. At the end of the Middle Ages, lapis lazuli began to be exported to Europe, where it was ground into powder and made into ultramarine, the finest and most expensive of all blue pigments. It was used by the most important artists of the Renaissance and Baroque, including Masaccio, Perugino, Titian and Vermeer, and was often reserved for the clothing of the central figure of the painting, especially the Virgin Mary. Today mines in Northeast Afghanistan are still the major source of lapis lazuli. Important amounts are also produced from mines west of Lake Baika in Russia, and in the Andes mountains in Chile. Smaller quantities are mined in Italy, Mongolia, the United States and Canada. Lapis takes an excellent polish and can be made into jewellery, carvings, boxes, mosaics, ornaments, and vases. There are many references to sapphires in the Old Testament, but most scholars agree that, since sapphires were not known before the Roman Empire, they most likely are references to lapis lazuli. For instance, Exodus 24:10: "As they saw the God of Israel, and there was under his feet as it were a paved work of a sapphire stone.." (KJV). The term used in the Latin Vulgate Bible in this citation is "lapidus sapphiri," the term for lapis lazuli.