When burned which substance forms a white powder to visualize a tool mark?

When magnesium ribbon is burned, this produces a white powdery film of magnesium oxide that help visualize a tool mark, which is usually a dark colored tool. They are used to highlight details during photography especially in forensic investigation. In addition, magnesium oxide may be smoked on the surface of an opaque material to form an integrating sphere and its reference white color is essential in colorimetry, due to its good diffusing and reflectivity properties.