Royal blue lapis lazuli comes from the silicate mineral lazurite. Polished stones often show gorgeous veins of white calcite and flecks of golden pyrite. Used by ancient civilizations from China to Sumeria, lapis lazuli inlay adorned the mask of ancient Egypt's King Tutankhamun. Lapis lazuli is somewhat rare and much of the deepest blue stone is mined in Afghanistan. Denim lapis has a lighter blue color and Aztec lapis features dramatic veining of black and brown minerals.