53. aluminium (ai) can occur in both tetrahedral and octahedral co-ordinations in silicates. the amount of octahedral al in a pyroxene crystal of composition mg

53. Aluminium (AI) can occur in both tetrahedral and octahedral co-ordinations in silicates. The amount of octahedral Al in a pyroxene crystal of composition Mg11 Feo5 Alos Sios Os 1S 1.4 0.4 0.4 1.8 6 answer in one decimal place). 54. The core-rim compositions of a normally zoned plagioclase crystal are as follows: Core: Cao1 Naos Ala Siz Os Rim: (give Cao.2 Nao.s Al Si3 Og .The amount of increase of Na atom from core to rim per formula unit of plagioclase is :_given answer in one decimal place). in 19 avvaan hasic the number of Ca cations in a garnet of chemical