Neat, this dovetails with another interest of mine, pottery. NaF is "sodium feldspar" and Ca-Si compounds are "wollastonite" among others. Both useful as fluxes

Neat, this dovetails with another interest of mine, pottery. NaF is "sodium feldspar" and Ca-Si compounds are "wollastonite" among others. Both useful as fluxes in metal casting, in addition to their pottery uses.