Sauconite Dimensions: 61 mm × 48 mm × 50 mm Locality: Botalaria Mine, Borriol, Castellón, Valencian Community, Spain Descripion: White massive sauconite on limonite matrix — Photo: Dan-Ioan Cimpean · Public domain
Sauconite
A zinc-rich smectite clay — soft earthy bluish-white masses in oxidized zinc deposits.
Intro adapted from Wikipedia (CC BY-SA).
Sauconite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₀.₃Zn₃(Si,Al)₄O₁₀(OH)₂·4H₂O.
It is a member of the Clay, Smectite-vermiculite structural group.
Key properties: Mohs hardness 1–2; Dull luster; optically biaxial.
IMA symbol Sau, grandfathered status — known before the IMA’s founding, named in 1875.
Fills vugs and seams in oxidized zinc and copper deposits; may be redeposited at the water table.
It is found associated with Hemimorphite, smithsonite, chrysocolla, coronadite, iron oxides.
The name refers to its occurrence in the Saucon Valley, Pennsylvania, USA.