In this chapter, we provide short discussions of some selected major Earth material resources that are used in our everyday existence.
The construction industry is the biggest user by far of sand and gravel, together with cement, dimension stone, and common clay. Sand and gravel is mined in every country in the world.
Steel is a major component in high-rise construction, ships, cars, bridges, appliances, and armaments. Energy supplies cannot be effective without pipelines, furnaces, and engines, which are usually made of steel. The original source of the iron used in steel making is found in iron-ore deposits, which are the iron-enriched products of sedimentary iron-formations. Iron deposits occur in most countries but large to very large iron deposits are restricted in number.
Clay minerals are hydrous aluminum silicates with layered structures that occur with a grain size of <2 µm in the largest dimension. Kaolinite (Sec. 10.4), Al2Si2O5(OH)4, is a primary constituent of kaolin. Another clay mineral, montmorillonite, with the approximate formula of (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2•nH2O, is the dominant clay mineral of bentonite, a major constituent of volcanic ash. This material has many technical applications. Vermiculite with an idealized formula of Mg3(Si,Al)4O10(OH)2· 4.5H2O[Mg]0.35 is another clay used in various commercial applications.