Parkinsonite
Parkinsonite is an IMA-recognized mineral species in the molybdate class, with the chemical formula Pb₇MoO₉Cl₂.
It crystallizes in the tetragonal crystal system. It is a member of the Asisite structural group.
Key properties: Mohs hardness 2–2.5; specific gravity 7.32; Scarlet to grenadine-red streak; Adamantine, pearly to resinous luster; optically uniaxial.
IMA symbol Pkn, IMA status: approved, named in 1991.
Found as a very rare mineral in nodules in manganese oxide ores in veins, fissures, and pockets in limestone.
It is found associated with Mendipite, chloroxiphite, diaboleite, cerussite, paralaurionite, wulfenite, calcite, manganese oxides (Merehead quarry, England).
The name refers to Reginald F.D. Parkinson (1928–), British mineral collector and dealer, Shepton Mallet, Somerset, England, who first found the mineral.