Teschenite

Teschenite is a type of igneous rock. Its name is derived from the town of Český Těšín, where it was discovered. The term crinanite has previously been used as a synonym for teschenite, however there have been attempts to standardize and stop its use. Rocks related to teschenite are referred to as rocks of the teschenite association.

Geological composition
Teschenite is a mixture of several minerals including titan-augite, analcime, various hornblendes, labradorite and in lesser quantities olivine. Teschenite also has subtypes such as lugarite.

History
Teschenite was first described and given a name by in 1861.

In 1866 teschenite occurrences with higher concentrations of magnesium were defined as picrite by Erich von Tschermak.

Until 1892 the name in use for the rock was tchesenit, which is derived from the German name for Český Těšín. The name teschenite (těšínit in Czech) was first used by mineralogist

In 1918 the same name was declared official by František Slavík.

Location of occurrence
Teschenite has been found in Scotland, Portugal, the Caucasus Mountains, Siberia, Kenya, Myanmar, Taiwan, Australia and New Zealand.

In the Czech Republic, teschenite is primarily found in the volcanic region of the Beskids which stretch from the borders of Moravia to regions east of Český Těšín. Specific documented deposits are in Tichá, in the basin of the Ostravice river, in the Řepiště municipality and in a quarry near Žermanice Reservoir.    Historically, olivine-rich teschenite has also been mined in an old quarry in Straník.