Nordstrandite Locality: Langesundsfjorden , Larvik , Vestfold , Norway ( Locality at mindat.org ) Field of view 6 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Nordstrandite
Nordstrandite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Al(OH)₃.
It crystallizes in the triclinic crystal system (space group I-1).
Key properties: Mohs hardness 3; specific gravity 2.41–2.43; Vitreous, pearly on cleavages luster; optically biaxial.
IMA symbol Nsd, IMA status: approved, named in 1958.
is commonly found in residual soils derived from limestones; in dolomitic oil shale, marine siltstone, chalk; in pegmatite, miarolitic cavities, and xenoliths in nepheline syenites.
It is found associated with Quartz, kaolinite, diaspore, goethite (Gunong Kapor, Borneo); natrolite, tetranatrolite, analcime, sodalite, albite, microcline, dawsonite (Mont Saint-Hilaire.
The name refers to Robert A. Van Nordstrand, Sinclair Research Laboratories, Harvey, Illinois, USA, who synthesized the compound, later named for him, then transferred to the natural mineral.