[L., azure stone.] The name of a mineral of a rich blue color, consisting chiefly of silica and alumina, with sulphates of soda, and iron in spots or veins. It is found in Persia, China, Chili, and Siberia, and is used for ornamental purposes, especially for inlaid work. In the marble palace built by the Empress Catherine at St. Petersburg there are entire apartments in-laid with lapis lazuli. It was much esteemed by the ancients, who used it for engraving and for vases.