In some paintings of the Italian Renaissance, crystalline crystals have been found mixed with pigments. The discovery was made by a conservation researcher at the National Gallery of Art in the United States, using an electronic microscope. The tiny parts of the crystal have been found in two colours of three Renaissance paintings: In the red of the dress of St.Catherine of Lotto and in the Nativity in red the red of the table of Josefen, and in the yellow of Tintoretto in the sea of Jesus Galilee.