LIGNITE (from Lat. lignum, wood). A min eral substance, which, like common coal, is of vegetable origin, but differs from it in often showing a distant fibrous or woody structure. The external form may also be preserved, and lignitized tree-trunks are not uncommon in many clay formations of recent geological age. Lignite has a brilliant lustre, conchoidal fracture. brown streak, and often open texture; in fact, it closely resembles charcoal. It contains from 55 to 65 per cent. of carbon, burns readily but with a smoky flame. and is inferior to true coal in its heating power. Owing to its open texture and the high percentage of moisture which it often contains, lignite disintegrates rapidly on exposure to the air, and hence it cannot be stored for a long period or transported to a great distance without danger of its crumbling to a powder. Lignite occurs in beds in the same manner as true coal. and forms large deposits in some for mations, especially those of Cretaceous and Ter tiary age.
The following table gives the composition of some American lignites: Deposits of lignite are known to occur in many parts of the world. including Central and South America, India, and China. It also occurs in large quantities in Europe and Great Britain, that mined in Germany being an important do inestic fuel. In the United States deposits of lignite are found in the Cretaceous and Tertiary formations of the \Vest, but there are practically no deposits of commercial importance in the East. Those best known in this country occur in Texas, New Mexico. Colorado, Utah, Wyo ming, Montana, North Dakota, Oregon, and Cali fornia; but since good bituminous coals occur in most of the States just mentioned, the lignites are at the present time of little commercial value. The markets for lignite are usually at no great distance from the mines. The presence of
lignite of fair quality in California is of indirect value, since it tends to exert a regnlating influ ence on the price of Australian coal imported into that State.
As a fuel lignite may be used in the form in which it is mined, or ground and pressed into blocks or bricklets, a small amount of bitumi nous matter being required to bind the material together. This is the form in which large quan tities of lignite are used in Germany. Lignite can also be utilized in the manufacture of pro ducer gas.
Jet is a variety of lignite of coal-black color. and so dense that it can be easily carved into small ornaments. It is stated by Professor Phillips to be a coniferous wood, and was first found at Whitby and other localities in England, having been known since early British times. Brown coal is another name for lignite, which is chiefly used in Europe. Borey coal is a local name used in Devonshire, where extensive beds occur.
BIBLIOGRAPHY. Bell, "On the Occurrence of Bibliography. Bell, "On the Occurrence of Lignite Around Hudson Bay," Canadian .hiring Rcriew, vol. xvi. (18951 : Da11, "Coal and Lig nite in Alaska," Serenteenth Annual Report, States Geological Surrey, Part I. (Wash ington. 1896) ; Durable, "Brown Coals and lig nites of Texas." Texas Geological SUrrey Report (Austin, 1892) ; Hills, "The Coal Fields of Colo rado," United Slates Geological Surrey, Mineral Resources (Washington. 18921 ; Turner, "The Coal Deposits of California," United Stales Geo logical Surrey. Mineral Resources INVa4lington, 1892) ; "Reconnaissance in the Rio Grande Coal Fields of Texas." Bulletin, railed States Geological Surrey (Washington, 1900i.