Prepd by high vacuum sublimation of a mixture of silicon and quartz: Schenk in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 696-697. Existence below 1200° in doubt; may disproportionate to a mixture of Si and SiO2: Benyon, Vacuum 20, 293 (1970). Review: Rochow in Comprehensive Inorganic Chemistry vol. 1, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 1353-1355.