BILLITON (Dutch, BLITOENG), island, Dutch East Indies, between Banka and Borneo and separated respectively by the Gaspar and Karimata straits. It forms an assistant-residency, under Sumatra. Roughly square in shape, it is 55m. long by 43 wide, and its area is 1,86osq.m. Included with it are small adjacent islands with an area of 95sq.m., which are sepa rated by narrow and mostly unnavigable channels. In physical structure and products it resembles Banka. Its coasts are sandy and very marshy, and though in the centre of the island a height of I,67oft. is reached (Mt. Tanjem), most of the land lies less than I 3of t. above sea-level, with groups of hills of granite or sedimentary formation rising from the flat or slightly undulating country; in the central parts there are treeless plains, covered with alang-alang grass. The geological formation is Devonian and granitic, with laterites. The average mean annual rainfall is 114.5in., with an average of 192 rainy days; the average mean temperature is 77°. Billiton, like Banka, has extensive tin de posits and forms the southern limit of the occurrence of this metal. The mines are worked largely by electrical power, with Chinese coolie labour, and by a private company, Government taking iths of the profits. In 1925-26, 162,700 piculs of tin were produced (I picul=136.23lb.). Trepang, tortoises, and edible birds' nests are found along the coast, and the woods yield timber for boat-building, and gum. Other products are coconuts and sago. Imports (1925), 4,420,389; exports, 34,228,054 gulden.
The pop. (1930) of Billiton is 73,429, 28,78o being foreign Asiatics, largely Chinese. The aborigines (Mohammedans, with some pagan beliefs) are akin to those of Banka, resembling the Bataks of Sumatra; on the coast there are Orang laut, or sea gypsies. The coast is a difficult one, beset with rocks and coral banks, but one river, the Cheruchup, is 1,300 to I,600ft. wide at its mouth (barred by a sandbank), and is tidal for seven miles and navigable as far as Cheruchup village. The best harbour is that of Tanjong Pandan, the capital of Billiton on the west coast. Billiton was formerly under the Sultan of Palembang, Sumatra, by whom it was ceded to the British in 1812. In the treaty of 1814, between the British and the Dutch, no mention was made of it, and the British at first refused to cede the island, only recognizing the Dutch claim in 1824.