what is it composed of?
Ferric iron
Goethite
Goethite is an iron oxyhydroxide containing ferric iron. 
what is the diameter of earth in km UNANSWERABLE what is the axial tilt of the planet? Approximately 23.439281° describe the internal structure of it? It is divided into layers by their chemical or physical (rheological) properties. For eg. the outer layer is a chemically distinct silicate solid crust. what is a silicate? In chemistry, it is any member of a family of anions consisting of silicon and oxygen. how is it detected? It reacts with molybdate anions yielding yellow silicomolybdate complexes. what is zeolite to it? The nature of soluble silicates is relevant to understanding biomineralization and the synthesis of aluminosilicates, such as the industrially important catalysts called zeolites. is it naturally occurring? Conventional open-pit mining techniques are used to mine natural zeolites. what is "biomineralization"? It is the process by which living organisms produce minerals, often to harden or stiffen existing tissues. mention a few of its applications? Organic macromolecules collect and transport raw materials and assemble the substrates and into short- and long-range ordered composites with consistency and uniformity. what is the relation of it with contaminating groundwater? It may be used to remediate groundwater contaminated with uranium. what are the other minerals produced from such a process? Magnetite, Goethite  and  pyrite any use of second mineral? Its main modern use is as an iron ore. where is it usually seen? England, Australia, Cuba, Michigan, and many other places.
wiki:8301037
Goethite [SEP] Composition
Goethite is an iron oxyhydroxide containing ferric iron. It is the main component of rust and bog iron ore. Goethite's hardness ranges from 5.0 to 5.5 on the Mohs Scale, and its specific gravity varies from 3.3 to 4.3. The mineral forms prismatic needle-like crystals ("needle iron ore") but is more typically massive. Feroxyhyte and lepidocrocite are both polymorphs of the iron oxyhydroxide FeO(OH) which are stable at the pressure and temperature conditions of the Earth's surface. Although they have the same chemical formula as goethite, their different crystalline structures make them distinct minerals. Additionally, goethite has several high-pressure and high-temperature polymorphs, which may be relevant to the conditions of the Earth's interior.