1) Sodium mineral 
Aphthitalite is a potassium sulfate mineral with the chemical formula: (K,Na)3Na(SO4)2. It was first described in 1835 for an occurrence on Mt. Vesuvius, Italy. The name is from the Greek άφθητος, `unalterable`, and άλας, `salt`, for its stability in air. It occurs as fumarolic incrustations in volcanic environments, as small crysta...
Arcanite