What is "fontarnauite"

Fontarnauite is a relatively recently described, rare borate mineral with the formula (Na,K)(Sr,Ca)(SO)[BO(OH)]·2HO. It is found in an evaporate boron deposit. It coexists with other evaporate boron minerals, especially probertite. It is monoclinic, crystallizing in the space group P2/c.

It was named in honour of Ramon Fontarnau i Griera, a materials scientist of the University of Barcelona.