Framework of silica tetrahedra? (each of the four Os shared) Number of Si and O for each tetrahedron Net charge: Framework of tetrahedra with every 4^th Si replaced with an Al ion? Number of Al, Si and O for each uparrow set of 4 tel. Al Si Net charge: Framework with every other Si replaced with an Al? Number of Al, Si and O for each set of 4 silica tetrahedra set of 4 Net charge: What common cation would balance the charges of the anionic complexes from all d. above isolated silicate Add it to d. to give downarrow chemical formula and downarrow mineral name downarrow Single chain silicate? Ion Double chain silicate with two hydroxyl ions (OH^-)_2 for every X sillica tetrahedra? Chem. Form, w OH^- and cation Sheet silicate with (OH^-)_2 for every silica tetrahedra? Chem. Form. w OH^-and cation Sheet silicate with (OH^-)_2 for every 4 sillica tetrahedra? (after every 4^th Si replaced with Al) Chem. Form, using K^+ and another cation Framework silicate? Framework of tetrahedra with every 4^th Si replaced with an Al ion? Chem. Form, for 4 tet. a cation Framework with every other Si replaced with an Al? Chem. Form, for 4 tet. and a cation