Four macroscopically visible B–E (rim) zones of the natural grossular-andradite garnet with Grs_58–64Adr_36–42Sps₂ composition were crystallographically studied. The applied procedure includes the Rietveld refinements of the crystal structures in a series of six space groups, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. It was established that it crystallized in the rhombohedral R‾3c space group. Various polyhedral distortions and structural order-disorder variations between the studied zones were also observed, determined and discussed. Therefore, rhombohedral symmetry of the studied grandite could be treated as primary and residual strain as the second cause for its slight optical anisotropy.

对具有 Grs _{58 –64} Adr _{36 –42} Sps ₂成分的天然粗钙长石榴石的四个宏观可见 B-E（边缘）区域进行了晶体学研究。应用程序包括对一系列六个空间群中的晶体结构进行 Rietveld 细化，然后对R值、位点占用因子以及键长和角度进行比较分析。确定它以菱面体R ‾ 3 c结晶空间群。还观察、确定和讨论了研究区域之间的各种多面体扭曲和结构有序-无序变化。因此，所研究的巨石的菱面体对称性可以被视为主要和残余应变作为其轻微光学各向异性的第二个原因。