Phase Equilibria in the System Lithium Metasilicate‐Forsterite–Silica

The primary fields of cristobalite, tridymite, Li 2 O·2SiO 2 , Li 2 O·SiO 2 , MgSiO 3 , Mg 2 SiO 4 , and a new compound, Li 2 O·MgO·SiO 2 , have been located for the system lithium metasilicate‐forsterite–silica. Most of the primary field for the compound Li 2 O·MgO·SiO 2 lies below the join Li 2 O·SiO2‐Mg 2 SiO 4 , but a small portion of it lies in the composition triangle Li 2 SiO 3 ‐Mg 2 SiO 4 ‐MgSiO 3 . The positions of four invariant points and three composition triangles have been established.