6 RES OUR CES What ar e c oal and miner als Not all of them Scientifcally a mineral is a naturally formed inorganic solid element or chemical compound with a limited range of chemical composition and an orderly internal atomic structure Coal and aggregates such as sand and gravel contain varying amounts of mineral matter but are technically rocks Coal is a carbonaceous sedimentary rock It is formed from organic matter and contains carbon and other elements such as hydrogen oxygen and nitrogen Most coal was formed 280 to 345 million years ago as trees ferns and other plants decomposed and were buried under prehistoric seas and swamps Pressure and temperature compressed and altered the plant remains con centrating carbon content and over millions of years transformed the material into coal Coal is divided into four major types based on the amount of transformation undergone from the earlier plant and peat stages heating value and other characteristics Lignit e is a coal with generally high moisture and ash content and low carbon content Signifcant re serv es are locat ed in Texas North Dakota and Montana Subbituminous c oal has a higher heating value than lignite Wyoming produces the bulk of sub bituminous coal in the Powder River Basin area Bituminous coal is a soft intermediate grade that is most common in the United States It is mined chiefy in Appalachia and the Midwest Anthracite is the hardest type of coal consisting of nearly pure carbon Mined in Pennsylvania it has the highest heating value and lowest mois ture and ash content Miner als also called nonfuel or hardrock min erals are clas sifed as metallic and nonmetallic Metalllic miner als ar e fur ther clas sified a s f e r r o u s a n d n o nf e r r o u s T h e c a t e go r y o f fe r r o u s m in e ra l s in c l u d e s ir o n a n d ir o n a l l o ys s u c h a s s t e e l N o n fe r r o u s m in e ra l s i n clu d e a m o n g m a n y o t h e r s c o p p e r s i l v e r p l a t in u m go l d u r a ni u m a n d z in c Nonmetallic minerals in clude structural ma terials st one sand gravel and synthetic ma terials lik e cement They usually are composed of some of the 25 most abundant minerals and are used for the nations infrastructure Nonmetallic miner als also include industrial minerals which are used as paper coatings paints varnishes enamels fertilizers abrasives and so f or th These minerals include sulfur salts limestone cla y s barite and industrial diamonds Coal copper gold gravel and iron ore are all mined but are they all minerals Is c oal being f ormed t oda y It s lik ely that the pr oc es s that f ormed c oal and other f os sil fuels is still oc curring in s w amp y ar eas wher e plant mat erial ac cumulat es Gold Or e