Single crystal of the rare borate mineral ezcurrite from the type locality: Tincalayu Mine, Salar Del Hombre Muerto, Salta, Argentina. — Photo: David Hospital · CC BY-SA 4.0
Ezcurrite
Ezcurrite is an IMA-recognized mineral species in the borate class, with the chemical formula Na₂B₅O₇(OH)₃·2H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 3; specific gravity 2.053; Vitreous to satiny luster; optically biaxial.
IMA symbol Ezc, grandfathered status — known before the IMA’s founding, named in 1957.
Probably formed from solutions derived from dehydration of borax in a discordant deposit in folded playa siltstones and sandstones.
It is found associated with Borax, kernite, halite.
The mineral was named to honor Juan Manuel de Ezcurra (1900–1970), Manager of the Compania Productora de Boratos, S.A., owner of the Tincalayu deposit, Argentina.