Mawbyite , Segnitite Locality: Alto das Quelhas do Gestoso Mines, Gestoso, Manhouce, São Pedro do Sul, Viseu District, Portugal Picture width 0.5 mm. Collection and photograph Christian Rewitzer Redbrown Mawbyite on yellow Segnitite. Analysed specimen — Photo: Christian Rewitzer · CC BY-SA 3.0
Mawbyite
A lead-iron-zinc arsenate approved in 1988, named for Maurice Mawby.
Intro adapted from Wikipedia (CC BY-SA).
Mawbyite is an IMA-recognized mineral species in the arsenate class, with the chemical formula PbFe³⁺₂(AsO₄)₂(OH)₂.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Natrochalcite structural group.
Key properties: Mohs hardness 4; specific gravity 5.365; Yellow-orange streak; Adamantine luster; optically biaxial.
IMA symbol Mby, IMA status: approved, named in 1988.
Found in an arsenic-rich reaction halo in fractures and cavities in a spessartine-quartz rock in the oxidization zone of a metamorphosed stratiform Pb–Zn orebody (Broken Hill, Australia).
It is found associated with Corkite–beudantite, adamite–olivenite, duftite, bayldonite, hidalgoite, pharmacosiderite, segnitite, Fe–Mn oxides (Broken Hill, Australia); mimetite.
The mineral was named to honor Sir Maurice Alan Edgar Mawby (1904–1977), Chairman of CRA, Ltd., for his contribution to the Australian mining industry and preservation of Broken Hill minerals.