Lepidocrocite (γ-FeO(OH)), also called
esmeraldite or
hydrohematite, is an
iron oxide-hydroxideA number of species are dubbed iron oxide-hydroxide. These chemicals are oxide-hydroxides of iron, and may occur in anhydrous or hydrated forms...
mineralA mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific...
. Lepidocrocite has an orthorhombic
crystal structureIn mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...
, a
hardnessThe Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science...
of 5, specific gravity of 4, a submetallic
lusterLustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. For example, a diamond is said to have an adamantine lustre and pyrite is said to have a metallic lustre...
and a yellow-brown streak. It is red to reddish brown and forms when
ironIron is a metallic chemical element with the symbol Fe and atomic number 26. Iron is a group 8 and period 4 element and is therefore classified as a transition metal. Iron and iron alloys are by far the most common metals and the most common ferromagnetic materials in everyday use...
-containing substances
rustRust is a general term for a series of iron oxides, usually red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture. Several forms of rust are distinguishable visually and by spectroscopy, and form under different circumstances...
underwater. Lepidocrocite is commonly found in the
weatheringWeathering is the decomposition of Earth's rocks, soils and minerals through direct contact with the planet's atmosphere. Weathering occurs in situ, or "with no movement", and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice,...
of primary iron minerals and in
iron oreIron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the form of magnetite , hematite , goethite, limonite or...
deposits.
Lepidocrocite (γ-FeO(OH)), also called
esmeraldite or
hydrohematite, is an
iron oxide-hydroxideA number of species are dubbed iron oxide-hydroxide. These chemicals are oxide-hydroxides of iron, and may occur in anhydrous or hydrated forms...
mineralA mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific...
. Lepidocrocite has an orthorhombic
crystal structureIn mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...
, a
hardnessThe Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science...
of 5, specific gravity of 4, a submetallic
lusterLustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. For example, a diamond is said to have an adamantine lustre and pyrite is said to have a metallic lustre...
and a yellow-brown streak. It is red to reddish brown and forms when
ironIron is a metallic chemical element with the symbol Fe and atomic number 26. Iron is a group 8 and period 4 element and is therefore classified as a transition metal. Iron and iron alloys are by far the most common metals and the most common ferromagnetic materials in everyday use...
-containing substances
rustRust is a general term for a series of iron oxides, usually red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture. Several forms of rust are distinguishable visually and by spectroscopy, and form under different circumstances...
underwater. Lepidocrocite is commonly found in the
weatheringWeathering is the decomposition of Earth's rocks, soils and minerals through direct contact with the planet's atmosphere. Weathering occurs in situ, or "with no movement", and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice,...
of primary iron minerals and in
iron oreIron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the form of magnetite , hematite , goethite, limonite or...
deposits. It can be seen as rust scale inside old
steelSteel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used such as manganese, chromium, vanadium, and tungsten...
water pipeWater pipes are pipes or tubes, frequently made of polyvinyl chloride , ductile iron, polyethylene, or copper, that carry pressurized and treated fresh water to buildings , as well as inside the building....
s and water tanks.
The structure of lepidocrocite is similar to the
boehmiteBoehmite or Böhmite is an aluminium oxide hydroxide mineral, a component of the aluminium ore bauxite. It is dimorphous with diaspore. It crystallizes in the orthorhombic dipyramidal system and is typically massive in habit. It is white with tints of yellow, green, brown or red due to impurities...
structure found in
bauxiteBauxite is the most important aluminium ore. It consists largely of the minerals gibbsite Al
3, boehmite γ-AlO, and diaspore α-AlO, together with the iron oxides goethite and hematite, the clay mineral kaolinite and small amounts of anatase TiO
2...
and consists of layered iron(III) oxide octahedra bonded by hydrogen bonding via
hydroxideIn chemistry, hydroxide is the name for the diatomic anion OH−, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known....
layers. This relatively weakly bonded layering accounts for the
scaley habit of the mineral.
It was first described in 1813 from the Zlaté Hory polymetallic
oreAn ore is a type of rock that contains minerals such as gemstones or metals that can be extracted through mining and refined for use. Samples of ore in the form of exceptionally beautiful crystals, exotic layering visible when sectioned or polished or metallic presentations such as large nuggets or...
deposit in
MoraviaMoravia is a historical region in central Europe in the east of the Czech Republic, one of the former Czech lands. It takes its name from the Morava River which rises in the northwest of the region.-Geography:...
,
Czech RepublicThe Czech Republic is a country in Central Europe that is sometimes considered to be Eastern European. The country borders Poland to the northeast, Germany to the west and northwest, Austria to the south and Slovakia to the east. The capital and largest city is Prague...
. The name is from the
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
lipis for
scale and
krokis for
fibre.