Mazzite-Na
Mazzite-Na is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₈(Si₂₈Al₈)O₇₂·30H₂O.
It crystallizes in the hexagonal crystal system (space group P6_3/mmc).
Key properties: specific gravity 2.16; White streak; Vitreous luster; optically uniaxial.
IMA symbol Maz-Na, IMA status: approved, named in 2003.
Filling cavities in basalt overlain by layers of silt and clay that are overlain by lacustrine deposits of silt and sodium borate with a few interbeds of rhyolite tuff. Likely affected by extensive sodium cation exchange.
It is found associated with Ferroan saponite, phillipsite-Na, gmelinite-Na, mordenite, clinoptilolite-Na, chabazite-Na, heulandite-Na, analcime.
Suffix, Na, signifies the sodium-dominant analog of mazzite-Mg.