Host: Japan Association of Mineralogical Sciences
Crystal structures of vanadian garnet from the Sor Rondane Mountains, East Antarctica, were analyzed to examine the structural variations caused by the substitution of V for Al. The atomic contents at the octahedral sites derived from EPMA analyses are as follows; Type 1 garnet (large porphyroblast): Fe0.01V0.08Cr0.02Ti0.03Al1.86, Type 2 garnet (garnet in kelyphite rim): Fe0.21V0.69Cr0.18Ti0.03Al0.99, Type 3 garnet (fine-grained porphyroblast): Fe0.20V0.96Cr0.23Ti0.03Al0.68. Unit cell parameters are 11.859 (type 1), 11.926 (type 2) and 12.0152 Å (type 3). The mean Y-O distances increases with increasing V in the octahedral site: 1.932 (type 1), 1.97 (type 2) and 1.987 A (type 3).
