Greyish crystals of extremely rare Fe-Al chlorohydroxide mineral zirklerite in halite matrix from the type and only known locality worldwide: Adolfsglück-Hope Mine, Schwarmstedt, Lower Saxony, Germany. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Zirklerite
Zirklerite is an IMA-recognized mineral species in the halide class, with the chemical formula (Fe,Mg)₉Al₄Cl₁₈(OH)₁₂·14H₂O.
Key properties: Mohs hardness 3.5; specific gravity 2.6; optically uniaxial.
IMA symbol Zkl, IMA status: questionable, named in 1928.
Occurs as the principal constituent of a rock composed of halite, anhydrite, quartz, and clay minerals, in brecciated layers intercalcated with halite and potash layers.
It is found associated with Halite, anhydrite, rinneite, dolomite, chlorite, quartz, clay minerals.
The name refers to Dr.-Ing. Zirkler, General Director of the Aschersleben Potash Works, Germany.