The present work deals with the oxidation behaviour of mechanically alloyed (MA) mixture of Al + B (Al-17.3 wt.% and B-82.7 wt.%) and aluminium boride (AlB12) in the air using thermogravimetric-differential thermal analysis (TG-DTA). An extent of oxidation (conversion, α) of 0.67 was observed f...

We study the high-pressure stability and elastic properties of Mg3Al2Si3O12 pyrope garnet using the density functional first principles computation method. Pyrope garnet is found to dissociate into an assemblage of MgSiO3 Mg-perovskite (Pv) and Al2O3 corundum (Cor) solid solutions at ∼19.7 GPa ...

High-pressure single-crystal/powder synchrotron X-ray diffraction was carried out on a hydrous pure magnesium pyrope (Mg3Al2Si3O12) containing 900 ppmw H2O, synthesized at 4.0 GPa and 1300 K. The pressure-volume (P-V) single-crystal data from room pressure to 9.81 GPa at ambient temperature were...

Cr-pyrope xenocrysts and associated inclusions of crichtonite-group minerals from the Internatsionalnaya kimberlite pipe were studied to provide new insights into processes in the lithospheric mantle beneath the Mirny kimberlite field, Siberian craton. Pyropes are predominantly of lherzolitic pa...

Numerous pyrope grains (group I; Prp62–72Alm14–24Grs(5–15Uv

This paper reports on the dose response and fading effect of the blue thermoluminescence (TL) emission of lithium-rich aluminosilicates (virgilite–petalite mixture) synthesized by sol–gel method and characterised by means of X-ray diffraction. This material could be potentially valid for dose ...

Processing of petalite concentrate from the Bikita deposits in Zimbabwe for production of high-purity Li2CO3 has been studied. XRF and ICP-OES analysis showed that the concentrate consists of oxides of Li, Si, and Al as major components, with an average Li2O content of 4.10%. XRD examination con...

A first study on the radioluminescence (RL) response of topaz synthesized is reported. Using three alternative and different compact reactants separately, i. e., aluminum oxide, aluminum hydroxide and kaolinite, synthesis tests by chemical vapor deposition (CVD) were conducted varying systematic...

Eastern Brazilian Pegmatite Province includes many topaz-bearing pegmatitic bodies. Residual melts from the Fe–K-rich alkaline Medina granite (ca. 500 Ma) formed the Serrinha pegmatite—a system of branched thin pegmatite veins hosted by pink facies of the parent granite. The colourless topaz f...

We examined the equation of state and high-pressure elasticity of the hydrous aluminosilicate mineral topaz-OH (Al2SiO4(OH)2) using first principles simulation. Topaz-OH is a hydrous phase in the Al2O3–SiO2–H2O (ASH) ternary system, which is relevant for the mineral phase relations in the hydr...

The colourless natural topaz stones were surface modified to beautiful yellow and green colour after heat treatment with lead oxide (PbO) and chromium oxide (CrO3), respectively. The surface of topaz shows a uniform colouration over the whole structure, which is confirmed by the UV–vis spectros...

The Qiguling topaz rhyolite is present as a dike within the Qitianling biotite granite batholith of the Nanling Range of southern China. Here, the rhyolitic dike, 4.5 m wide and 500 m long, contains enclaves of topaz granite. These rhyolites contain up to 72 wt.% SiO2, have alumina saturation in...

The aim of this work is to design fast neutron irradiation channels for topaz irradiation at Egypt Second Research Reactor (ETRR-2) by shielding the aluminum boxes, used for topaz irradiation, with B4C (boron carbide) or manufacturing the irradiation boxes from aluminum contains boron. This in t...

Electron irradiation was performed on topazes of two origin from Mogok valley of Mandalay, in Myanmar and Yen Bai province, in Vietnam. The samples were irradiated with 20 MeV electron beam (e-beam) to fluences of 1.34×1016 cm-2 and 2.65×1016 cm−2, respectively. Their characteristic spectra we...

Albeit the thermoluminescent properties of both Al2O3 and natural topaz have been documented, owing to a controlled composition, the prospective of synthetic topaz for dosimetry applications is expected to be further promising. In this contribution, the thermoluminescent (Tl) properties of synth...

Nuclear power and thermionic conversion can serve as a compact, durable energy source for the space exploration and exploitation. In this paper, the modified Reactor Excursion and Leak Analysis Program5 (RELAP5) with the implement of NaK-78 eutectic alloy (78%K and 22%Na) properties and heat tra...

The optically stimulated luminescence (OSL) properties under beta radiation of synthetic topazes produced from three different reactants are reported for the first time. Topazes were synthesized by chemical vapor deposition using sodium hexafluorosilicate (Na2SiF6) compacts as solid precursor an...

The structures of kaolinite, calcite and corundum were strongly deteriorated with activating the mixture with high energy planetary mono mill. Anorthite formation kinetics of activated and non-activated mixtures were studied by Differential Thermal Analysis under a heating rate of 5–30 °C, usi...

The scope of the present study is to develop alternative white porcelain stoneware tile compositions without using zircon (ZrSiO4) which have shown better whiteness values than standard white porcelain stoneware tile composition containing zircon. These new compositions are designed to develop a...

We report convection-free anorthite dissolution experiments in a basaltic melt at 1280–1500 °C and 0.5 GPa on two different crystallographic surfaces, (121¯) and (3¯02) to investigate dissolution kinetics. The anisotropy of the anorthite dissolution rate along these two surfaces is negligibl...