Black-band ironstone, 2.1 billion years old

Ironstone is a fine-grained, heavy and compact sedimentary rock. Its main components are the carbonate or oxide of iron, clay and/or sand. It can be thought as a concretionary form of siderite. Ironstone also contains clay, and sometimes calcite and quartz. Image File history File links Download high resolution version (2692x1936, 1704 KB) File links The following pages link to this file: Banded iron formation Ironstone ... Image File history File links Download high resolution version (2692x1936, 1704 KB) File links The following pages link to this file: Banded iron formation Ironstone ... Two types of sedimentary rock: limey shale overlaid by limestone. ... Siderite is also the name of a type of iron meteorite. ... Calcite from Brushy Creek Mine, Missouri, USA. The mineral calcite is a calcium carbonate corresponding to the formula CaCO3 and is one of the most widely distributed minerals on the Earths surface. ... Quartz is the most abundant mineral in the Earths crust. ...

Appearance

Freshly cleaved ironstone is usually gray. The brown external appereance is due to oxidation of its surface. Ironstone, being a sedimentary rock is not always homogeneous, and can be found in a red and black banded form called tiger iron, sometimes used for jewelry purposes. The most fundamental reactions in chemistry are the redox processes. ... Polished tigers eye gemstone Tigers eye (also Tigers eye, Tiger eye) is a chatoyant gemstone that is usually yellow- to red-brown, with a silky luster. ... Jewelry (the American spelling; spelled jewellery in Commonwealth English) consists of ornamental devices worn by persons, typically made with gems and precious metals. ...

Sometimes ironstone hosts concretions or opal gems. A concretion is a solid mineral inclusion within a rock strata that is oval or spherical in shape. ... OPAL is also the name of one of the four detectors of the Large Electron-Positron Collider. ...

Occurrence

Ironstone mostly occurs in the form of nodules. It is easy to find ironstone overlying coal measures. Coal is a fossil fuel extracted from the ground by deep mining, coal mining (open-pit mining or strip mining). ...

Ironstone as a source of iron

Ironstone is a bountiful and widespread source of iron (Fe), although it only contains >50% iron, far less than the other main source of iron, hematite. Most of British iron originates from ironstone. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Hematite (AE) or haematite (BE) is the mineral form of Iron (III) oxide, (Fe2O3), one of several iron oxides. ...

See also: Iron ore. This heap of iron ore pellets will be used in steel production. ...