Black-band ironstone, 2. 1 billion years old

Ironstone is a fine-grained, heavy and compact sedimentary rock. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Its main components are the carbonate or oxide of iron, clay and/or sand. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles It can be thought as a concretionary form of siderite. Siderite is also the name of a type of Iron Meteorite. ---- Siderite is a Mineral composed of Iron Carbonate Fe[[carbon Ironstone also contains clay, and sometimes calcite and quartz. Calcite is a carbonate mineral and the most stable polymorph of Calcium carbonate ( Ca[[carbon C]] O 3 Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in

Appearance

Freshly cleaved ironstone is usually grey. The brown external appearance is due to oxidation of its surface. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state 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. Tiger's eye (also Tigers eye, Tiger eye) is a chatoyant Gemstone that is usually yellow- to red-brown with a silky luster. Jewellery (also spelled jewelry, see spelling differences) is a personal Ornament, such as a necklace ring or bracelet made from Gemstones

Sometimes ironstone hosts concretions or opal gems. A concretion is a volume of Sedimentary rock in which a Mineral cement fills the porosity (i OPAL ( Open Pool Australian Lightwater reactor) is a 20 megawatt pool-type nuclear research reactor that was officially opened in April 2007

Occurrence

Ironstone mostly occurs in the form of nodules, for example in seams in the coal measures. The Coal Measures is a lithostratigraphical term used mainly in the British Isles for the coal-bearing part of the Upper Carboniferous System

Uses

Due to its unique properties, ironstone was once popular for use in English tea sets

Ironstone as a source of iron

Ironstone is a bountiful and widespread source of iron (Fe), although it only contains less than 50 percent iron, far less than the other main source of iron, hematite. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland A tea set, in the Western tradition is a suite of dishes sold in a group for use at Afternoon tea or a formal Tea party. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Hematite, also spelt hæmatite, is the Mineral form of Iron(III oxide (Fe2O3 one of several Iron oxides Historically, most of British iron originated from ironstone, but it is now rarely used for this purpose.

See also

• Iron ore
• Banded iron formation