Black crystals of the rare mineral jeppeite from the TL in Australia (Walgidee Hills, Noonkanbah Station, Derby-West Kimberley Shire, Western Australia, Australia). Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Jeppeite
Jeppeite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula (K,Ba)₂(Ti,Fe³⁺)₆O₁₃.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Jeppeite structural group.
Key properties: Mohs hardness 5–6; specific gravity 3.94; Pale brown streak; Submetallic luster; optically biaxial.
IMA symbol Jep, IMA status: approved, named in 1980.
Found in some abundance, in a large weathered lamproite plug.
It is found associated with Priderite, celadonite, chlorite, titanite, shcherbakovite, wadeite, perovskite, apatite, richterite, calcite.
The name refers to Dr. John Frederik Biccard Jeppe (1920–), geologist of Nedlands, Western Australia, discoverer of the mineral.