Stishovite - Wikipedia
Stishovite is an extremely hard, dense tetragonal form of silicon dioxide. It is very rare on the Earth's surface; however, it may be a predominant form of silicon dioxide in the Earth, especially in the lower mantle .
斯石英 - 百度百科
斯石英是 石英 更致密的高压相多型体，密度为4.35g/cm 3， 八面体 配位，具有 金红石 结构， 空间群 P42/mnm。. 由共用边八面体链组成，形成通道平行于c轴，d=0.206nm。. 斯石英易受冲击热效应破坏，保存量很少，故在镜下通常不易辨别，只能用 X射线 来鉴别，有5 ...
Evidence of shock-compressed stishovite above 300 GPa
Jun 23, 2020 · Here, laser-induced shock compression experiments at the LCLS- and SACLA XFEL light-sources elucidate the high-pressure behavior of stishovite on the lattice-level under in situ conditions on the...
Stishovite | High-Pressure, Silicon-Dioxide, Superhard | Britannica
Stishovite, high-pressure, metastable polymorph of silica (SiO2), having a rutile-type tetragonal structure; silicon is in six-fold coordination with oxygen while each oxygen atom is shared with three silicon atoms. Stishovite was first discovered in …
Silica-water superstructure and one-dimensional superionic
Sep 1, 2023 · Stishovite (Stv) is a high-pressure polymorph of silica (SiO 2) and could occupy ~23% by volume in the subducted oceanic crust (10, 11). It is known as a NAM but recent experiments (12–14) revealed intriguing water incorporation phenomena in high-pressure synthesized Stv.
Stishovite - an overview | ScienceDirect Topics
Stishovite pseudomorphs: Stishovite is a high pressure phase of SiO2, stable at 9–10GPa, and previously identified only in meteorites and impact craters. From: Encyclopedia of Geology (Second Edition), 2021
Evidence for the stability of ultrahydrous stishovite in Earth ... - PNAS
At higher pressures, stishovite, a tetragonal phase with a rutile structure (P4 2 /mnm) and with silicon in octahedral coordination with oxygen, is stable up to ∼70 GPa along a mantle geotherm, where it transforms through a second-order displacive phase transition to an orthorhombic CaCl 2 -structured phase (27 – 29).
Water speciation and hydrogen isotopes in hydrous stishovite ...
Jul 19, 2023 · Stishovite is a key mineral for understanding the deep Earth water cycle because of its potential as a main carrier for water into the transition zone and lower mantle.
Fracture-induced amorphization of polycrystalline SiO2 stishovite…
Oct 9, 2014 · Our experimental results show that fracture of SPs induces solid-state amorphization of stishovite (amorphization was not detected in the SP with T S = 2000°C) and that the formed amorphous ...
Sound Velocities in Shock-Synthesized Stishovite to 72 GPa
Nov 21, 2019 · Stishovite (rutile-type SiO 2) is the archetype of dense silicates and may occur in postgarnet eclogitic rocks at lower-mantle conditions. Sound velocities in stishovite are fundamental to understanding its mechanical and thermodynamic behavior at …