Wikipedia
Hydroterskite
Hydroterskite is a rare zirconium silicate mineral, related to terskite (hence its name), with the formula NaZrSiO(OH). It was discovered in the Saint-Amable sill near Montréal, Québec, Canada. It is hydrous, when compared to terskite. Chemically similar minerals include litvinskite and kapustinite.