Dubrovinsky L, Sharp TG, Saxena SK, Chen M
Max-Planck-Institut fur Chemie, J.-Becher-Weg 27, D-55128 Mainz, Germany. Theoretical Geochemistry Program, Institute of Earth Sciences, Uppsala University, S-75236, Uppsala, Sweden. Department of Geology, Arizona State University, Tempe, A.
Science. 2000 Jun 2;288(5471):1632-5. doi: 10.1126/science.288.5471.1632.
A post-stishovite phase of silica was identified in the Shergotty meteorite by x-ray diffraction and field emission scanning electron microscopy. The diffraction pattern revealed a monoclinic lattice, similar to the baddeleyite-structured polymorph with the cell parameters a = 4.375(1) angstroms, b = 4.584(1) angstroms, c = 4. 708(1) angstroms, beta= 99.97(3), rho = 4.30(2) grams per cubic centimeter, where the numbers in parentheses are the maximum deviations. Transmission electron microscopy investigations indicate the presence of the alpha-lead dioxide-like polymorph, stishovite, and secondary cristobalite in the same silica grain. The mixture of high-density polymorphs suggests that several post-stishovite phases were formed during the shock event on the Shergotty parent body.
通过X射线衍射和场发射扫描电子显微镜在谢格蒂陨石中鉴定出了一种二氧化硅的后斯石英相。衍射图谱显示为单斜晶格，类似于具有以下晶胞参数的斜锆石结构多晶型体：a = 4.375(1)埃，b = 4.584(1)埃，c = 4.708(1)埃，β = 99.97(3)，ρ = 4.30(2)克每立方厘米，括号中的数字为最大偏差。透射电子显微镜研究表明，在同一二氧化硅颗粒中存在α-二氧化铅类多晶型体斯石英和次生方石英。高密度多晶型体的混合物表明，在谢格蒂母体的冲击事件中形成了几种后斯石英相。
