1) Sodium mineral 
Combeite is a rare silicate mineral with the formula Na2Ca2Si3O9. It has a trigonal crystal system. ==Discovery and occurrence== It was first described in 1957 for an occurrence in nephelinite lavas and tephra on Mt. Nyiragongo, Goma, Kivu, Democratic Republic of Congo (then Zaïre). It has also been reported from the Bellerberg volcano in Ettring...