Hercynite
Encyclopedia
Hercynite is a spinel
mineral
with the formula FeAl2O4.
It occurs in high-grade metamorphosed
iron rich argillaceous sediment
s as well as in mafic
and ultramafic igneous rock
s. Due to its hardness it also is found in placer
s.
It was first described in 1847 and its name originates from the Latin name for the Bohemian Forest
, Silva Hercynia, where the species was first found.
Spinel
Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...
mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
with the formula FeAl2O4.
It occurs in high-grade metamorphosed
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...
iron rich argillaceous sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s as well as in mafic
Mafic
Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron; the term is a portmanteau of the words "magnesium" and "ferric". Most mafic minerals are dark in color and the relative density is greater than 3. Common rock-forming mafic minerals include olivine,...
and ultramafic igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
s. Due to its hardness it also is found in placer
Placer
Placer may refer to one of the following:*Placer deposit*Placer sheep*Placer mining*Placer, rugby league football role.Geographical names:* Placer, Masbate, Philippines* Placer, Surigao del Norte, Philippines...
s.
It was first described in 1847 and its name originates from the Latin name for the Bohemian Forest
Bohemian Forest
The Bohemian Forest, also known in Czech as Šumava , is a low mountain range in Central Europe. Geographically, the mountains extend from South Bohemia in the Czech Republic to Austria and Bavaria in Germany...
, Silva Hercynia, where the species was first found.