Class : Silicates
    Subclass : Inosilicates
    Crystal system : Triclinic
    Chemistry : Ca₂(Mg,Fe,Ti)₆(Si,Al)₆O₂₀
    Rarity : Rare

Rhönite is a rare silicate of the aenigmatite group, present in alkaline magmas deficient in silica, of basic to intermediate composition, where it accompanies titaniferous augite and feldspathoids ; it is also found in contact with alkaline basalt and limestones. It is a mineral that is mainly primary, sometimes secondary and developing at the expense of amphiboles. Its composition is quite fluctuating, titanium in particular being present in variable quantities. It owes its name to its discovery location : the Rhön Mountains (Germany). Rhönite forms prismatic or tabular crystals of several centimeters, skeletal grains or aggregates of dark brown to black color.

Main photo : Rhönite from Nickenicher Sattel, Germany © Edgar Müller

Cruciform twins are known with 2 and 3 individuals forming 4 and 6-pointed stars.

No fakes listed for this mineral species.