Planerite Locality: Mt Ida , Montgomery County, Arkansas , USA ( Locality at mindat.org ) Size: miniature, 3.6 x 2.4 x 2.3 cm Planerite Superb locality specimen of the aluminum phosphate, planerite: rare for the locality and just a pretty miniature that would stand out in any group of Arkansas minerals, few of which have any color like this to them. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Planerite
Planerite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₆(PO₄)₂(PO₃OH)₂(OH)₈·4H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Turquoise structural group.
Key properties: Mohs hardness 5; specific gravity 2.65–2.68; Dull, chalky to earthy luster.
IMA symbol Pnr, IMA status: approved, named in 1862.
A rare secondary mineral formed in phosphate-rich aluminous deposits.
It is found associated with Wavellite, variscite, metavariscite (Mt. Ida, Arkansas, USA).
The mineral was named to honor Dimitrii Ivanovich Planer (1821–1882), mineralogist and Director of the Gumeshevsk copper mines, Polevskoi, Russia.