Topic
Uvarovite
About: Uvarovite is a research topic. Over the lifetime, 109 publications have been published within this topic receiving 2075 citations. The topic is also known as: Uv.
Papers published on a yearly basis
Papers
TL;DR: In this article, the single-crystal polarized Raman spectra of four natural silicate garnets with compositions close to end-members almandine, grossular, andradite, and uvarovite, were measured, along with the powder Spectra of synthetic pyrope-grossular and Almandine-spessartine solid solutions.
Abstract: The single-crystal polarized Raman spectra of four natural silicate garnets with compositions close to end-members almandine, grossular, andradite, and uvarovite, and two synthetic end-members spessartine and pyrope, were measured, along with the powder spectra of synthetic pyrope-grossular and almandine-spessartine solid solutions. Mode assignments were made based on a comparison of the different end-member garnet spectra and, in the case of pyrope, based on measurements made on additional crystals synthesized with 26Mg. A general order of mode frequencies, i.e. R(SiO4)>T(metal cation)>T(SiO4), is observed, which should also hold for most orthosilicates. The main factors controlling the changes in mode frequencies as a function of composition are intracrystalline pressure (i.e. oxygen-oxygen repulsion) for the internal SiO4-vibrational modes and kinematic coupling of vibrations for the external modes. Low frequency vibrations of the X-site cations reflect their weak bonding and dynamic disorder in the large dodecahedral site, especially in the case of pyrope. Two mode behavior is observed for X-site cation vibrations along the pyrope-grossular binary, but not along the almandine-spessartine join.
209 citations
TL;DR: In this article, the authors studied the plastic properties of materials with garnet structure under wide temperature conditions, ranging from room temperature to ∼95% of the melting temperatures, using uniaxial compression and hot microhardness tests.
181 citations
TL;DR: In this paper, a general model is presented as to the approximate mixing properties of multicomponent natural garnet solid solution involving substitutions in both eight and six coordinated sites and the stability of the solid solution with respect to phase separation in the ternary system has been analyzed.
Abstract: Approximate mixing properties of the dominant calcium silicate end-member components of natural garnets, namely grossularite, andradite and uvarovite, have been derived through theoretical thermodynamic and crystal chemical analysis, and appropriate reduction of the available experimental data. The stability of the solid solution with respect to phase separation in the ternary system has been analyzed. Finally, a general model is presented as to the approximate mixing properties of multicomponent natural garnet solid solution involving substitutions in both eight and six coordinated sites.
154 citations
TL;DR: The adiabatic single-crystal elastic properties of synthetic end-member uvarovite garnet (Ca3Cr2Si3O12) and a natural sample of 96% andradite garnets ( Ca3Fe2Si 3O12)-and-Uv have been measured at ambient conditions by Brillouin spectroscopy as mentioned in this paper.
Abstract: The adiabatic single-crystal elastic properties of synthetic end-member uvarovite garnet (Ca3Cr2Si3O12) and a natural sample of 96% andradite garnet (Ca3Fe2Si3O12) have been measured at ambient conditions by Brillouin spectroscopy. The bulk modulus (Ks) and shear modulus (μ) of andradite (And) are Ks = 158 ± 2 GPa, μ = 90 ± 1 GPa, and those of uvarovite (Uv) are Ks = 165 ± 2 GPa and μ = 94 ± 1 GPa. Observed trends of the single-crystal elastic moduli (Cij) as a function of composition, and specifically the deviation from the Cauchy relation c12 = C44 are analogous between the Ca-bearing garnets grossular (Gr = Ca3Al2Si3O12)-And-Uv and other chemical systems such as the rock salt and corundum structure oxides, whereas other silicate garnets exhibit distinctly different behavior. Ks of andradite is substantially higher than previously estimated from data on garnet solid solutions. Garnets on the Gr-And join show a pronounced minimum in the Ks-composition relationship at a composition of approximately Gr24And76, indicating that ideal linear mixing of end-member elastic properties is inadequate to explain the elasticity of garnet solid solutions. The elastic properties of Gr-And and Al2O3-Cr2O3 solid solutions can be explained by incorporating a composition-dependent volume of mixing term into the expression for solid-solution elasticity. An evaluation of elasticity systematics relating the bulk sound speed and mean atomic weight, or Ks and molar volume, indicates that these relationships yield closer estimates of garnet elastic properties than does the seismic equation of state of Anderson (1967).
117 citations
TL;DR: In this paper, the elasticities of six polycrystalline silicate garnets (almandine, grossular, pyrope, uvarovite, andradite) have been experimentally studied at pressures up to 3.0 GPa using a phase comparison method with an ultrasonic interferometer in a liquid cell piston-cylinder apparatus.
Abstract: The elasticities of six polycrystalline silicate garnets (almandine, grossular, pyrope, uvarovite, andradite, and Prp 25 Alm 56 Spe 19 ) have been experimentally studied at pressures up to 3.0 GPa using a phase comparison method with an ultrasonic interferometer in a liquid cell piston-cylinder apparatus. Complete elasticity data sets (P- and S-wave velocities, bulk moduli K s , shear moduli G, and their first pressure derivatives K S ′ and G ′) have been obtained for all six garnets, and are used together with an up-to-date compilation of garnet elasticity data to examine composition-elasticity systematics of garnets. Our results suggest that pyralspite and ugrandite have different relationships between bulk sound velocity (V ϕ ) and mean atomic weight (M 0 ), between Poisson’s ratio (σ) and density (ρ), and between G / K s and K s /ρ ratios. A large error may occur when the systematics are applied across different garnet groups.
91 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2019 | 5 |
| 2018 | 3 |
| 2017 | 1 |
| 2016 | 1 |
| 2015 | 2 |