Georgerobinsonite
A lead chromate-fluoride-chloride with tiny transparent orange-red crystals, named for mineralogist George Robinson.
Intro adapted from Wikipedia (CC BY-SA).
Georgerobinsonite is an IMA-recognized mineral species in the chromate class, with the chemical formula Pb₄(CrO₄)₂(OH)₂FCl.
It crystallizes in the orthorhombic crystal system (space group Pmmn).
Key properties: Mohs hardness 2.5–3; specific gravity 3.54; Pale orange streak; Adamantine luster.
IMA symbol Grb, IMA status: approved, named in 2009.
Found in vugs in silicified rock in a deeply weathered gold-silver-molybdenum-lead-zinc- vanadium, hydrothermal mineral deposit.
It is found associated with Caledonite, a cerchiaraite-related mineral, cerussite, diaboleite, Cr-bearing leadhillite, matlockite, murdochite, pinalite, wulfenite, yedlinite, quartz.
The mineral was named to honor Dr. George Willard Robinson (b. 1946), mineral curator, researcher, teacher, and field collector.