BAUXITE, boks'it (from Balls; see below). The must important ore of aluminum, a hydrate having the composition though most occurrences contain also some silica, iron oxide, and titanium. The ()re occurs in rounded grains, in pisolitic or claylike masses. The grains usu ally show a concentric structure and a variable color from white to yellow, brown. or red. It is named from its occurrence at Baux, in France, hut it is also known from Styria and Carin thia. in Austria. and from Antrim. in Ireland. In the United States it occurs in a belt about GO miles long, extending from northwestern Geor gia into northeastern Alabama, and also in Ar kansas, near Little Rock. The foreign deposits result from the chemieal alteration of igneous rocks: the American deposits are thought to be hot-spring formations. Those of Alabama and Georgia are basin-shaped, and are limited ver tieally to points between 900 and 950 feet above sea-level. The composition of good-grade Ameri
can ore is approximately as follows: Alumina, 57 to 62 per cent.; ferric oxide, under 1 per cent.: silica, 2.5 to :3 per cent.: titanic acid, 3 to 4 per cent.; water (combined), 20 to 30 per cent. ; moisture. retained mechanically, 2 to 4 per cent. While bauxite serves chiefly as an ore of aluminum, it is also employed in the manufacture of alum, and for lining basic con verters and Siemens-Martin furnaces in the manufacture of steel. Consult: Ilayes, "Baux ite," Sixteenth annual Report United States Geological Surrey, Part 3 (Washington, 1895) ; Mince-al Industry, Vol. II. (New York, 1893) ; Branner, "The Bauxite Deposits of Arkansas," Journal of Geology, Vol. V. (Chicago, 1.897). See, also, the articles on ALUM and ALUMINIUM.