Gebhardite
Gebhardite is an IMA-recognized mineral species in the halide class, with the chemical formula Pb₈As³⁺₄O₁₁Cl₆.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: Mohs hardness 3; specific gravity 6; White streak; Adamantine luster; optically biaxial.
IMA symbol Geb, IMA status: approved, named in 1979.
On a specimen of highly oxidized ore from the lower oxidation zone of a dolostone-hosted hydrothermal polymetallic ore deposit.
It is found associated with Reinerite, mimetite, smithsonite, willemite, hematite, fraipontite, quartz.
The mineral was named to honor Dr. Georg Gebhard (1945–), German chemist, mineral collector, and authority on rare minerals, who supplied the specimen.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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