1) Sodium mineral 
Nabesite is a rare silicate mineral of the zeolite group with the chemical formula Na2BeSi4O10·4(H2O). It occurs as colorless to white orthorhombic crystals in thin platy mica like sheets. It has the zeolite structure. Its Mohs hardness is 5 to 6 and its specific gravity is 2.16. The reported refractive index values are nα=1.499, nβ=1.507, and ...