Anorthite

Définitions de « anorthite »

Anorthite - Nom commun

• Espèce minérale appartenant au groupe des silicates, sous-groupe des tectosilicates, caractérisée par la formule chimique CaAl2Si2O8.

  On peut regarder ces deux feldspaths comme de l’anorthite impure.

Étymologie de « anorthite »

Évolution historique de l’usage du mot « anorthite » depuis 1800

Citations contenant le mot « anorthite »

• L’utilisation de l’anorthite d’origine terrestre comme simulant du matériau lunaire fonctionne bien, malgré des facteurs externes qui peuvent entraîner de petits changements dans sa composition au fil du temps. En tant que simulant, il peut être utilisé pour tester une variété d’équipements qui feront bientôt leur chemin vers la surface lunaire dans le cadre des missions Artemis.

• To investigate the stability of the discovered high-pressure variants of feldspars at high temperatures and their possible persistence in Earth's interior, the scientists performed a series of high-pressure-high-temperature experiments at the Bayerisches Geoinstitut. It turned out that the high-pressure variant of anorthite persists at temperatures up to 600 degrees Celsius at 15 GPa.

• But even the high quality anorthite from the Stillwater Complex is not perfect. Terrestrial influences like temperature and pressure, or exposure to water, can alter the mineral. Scientists have long studied the best way to mill, mix, and handle the materials to arrive at the most Moon-like dust possible.

• The soil mainly includes minerals olivine, pyroxene, anorthite and glass bead. To avoid possible chemical contamination and ion-bombing-induced amorphization, they do not employ the focused ion beam (FIB) to cut the bulk samples except glass bead. Firstly, they unambiguously identify the wüstite FeO nanoparticles instead of npFe0 that are embedded in amorphous SixOy rims outside the olivine grains. This unique rim structure has not been reported for any other lunar, terrestrial, Martian, or meteorite samples so far.

• However, it turns out that a lack of iron would make Mercury’s original magma ocean less dense than the moon’s, so that any anorthite crystals that grew would sink rather than floating upwards to produce bright spots. In fact, the only mineral likely to crystallise that would have been able to float is graphite, the soft, dark form of carbon used in pencil “lead”.

• Here, we consider the energetics of water and carbon dioxide adsorption by examining the first layer of molecules adjacent to the Ca-rich anorthite surface as extracted from the AIMD simulations with water and scCO2 molecules over the mineral, respectively. The extracted structures are optimized to obtain the structure of a stand-alone monolayer of H2O and CO2, see Supplementary Figs 1 and 2 Table 1, we summarize the adsorption energies per molecule at full-monolayer coverage on the Ca-rich face of the anorthite (001) surface and compare to single-molecule adsorption. For the estimation of the energies, the following formulae were used:

Traductions du mot « anorthite »

Sources et ressources complémentaires

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