Class : Silicates
    Subclass : Inosilicates
    Crystal system : Monoclinic
    Chemistry : Ca₂Mg₃Al₂(Si₆Al₂)O₂₂(OH)₂
    Rarity : Rare

Tschermakite is a calcium-magnesium amphibole, formerly considered a variety of green hornblende, it is now recognized as a mineral in its own right. It forms a continuous series with ferrotschermakite, its iron-bearing equivalent. Tschermakite is found mainly in metamorphic rocks of the upper amphibolite facies, in ultrabasic rocks and eclogites, in association with kyanite. It was named in honor of Gustave Tschermak von Seysenegg, Professor of Mineralogy at the University of Vienna (Austria). Tschermakite occurs in prismatic crystals that are often stocky with a hexagonal section, rarely doubly terminated. It is also common in masses or aggregates that are more or less fibrous to bacillary, sometimes grainy. Its color is green to green-black.

Main photo : Tschermakite from Varatskoe, Karelia, Russia © Pavel Kartashov

Single or multiple twins parallel to {100} are known.

No fakes listed for this mineral species.