Bobshannonite
Bobshannonite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₂KBa(Mn,Na)₈(Nb,Ti)₄(Si₂O₇)₄O₄(OH)₄(O,F)₂.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Seidozerite-Bafertisite structural group.
Key properties: Mohs hardness 4; specific gravity 3.787; Very pale brown streak; Vitreous to frosted luster.
IMA symbol Bsha, IMA status: approved, named in 2014.
A hydrothermal phase in a pegmatite in association with an intrusive alkaline gabbro- syenite complex.
It is found associated with Sérandite, albite, aegirine, epididymite, catapleiite, kupletskite, rhodochrosite, rhabdophane-(Ce).
The mineral was named to honor Dr. Robert (Bob) D. Shannon (b. 1935) from Boulder, Colorado, USA.