Silicate mineralogy

ROUMAITE, (Ca,Na,□) 3 (Ca,REE,Na) 4 (Nb,Ti)[Si 2 O 7 ] 2 (OH)F 3 , FROM ROUMA ISLAND, LOS ARCHIPELAGO, GUINEA: A NEW MINERAL SPECIES RELATED TO DOVYRENITE

Titanium / Silicate mineralogy / Niobium