Mineral sources are rutile, ilmenite, and leucoxene (a weathering product of ilmenite). Ninety-three to 96% of rutile consists of titanium dioxide, ilmenite may contain between 44% and 70% TiO 2 and leucoxene concentrates may contain up to 90% TiO 2. In addition, a high-TiO 2 slag is produced from ilmenite that contains 75–85% TiO 2.