Academic literature on the topic 'Material like kyanite'

Abstract A series of tourmaline reference materials are developed for in situ oxygen isotope analysis by secondary ion mass spectrometry (SIMS), which allow study of the tourmaline compositions found in most igneous and metamorphic rocks. The new reference material was applied to measure oxygen isotope composition of tourmaline from metagranite, meta-leucogranite, and whiteschist from the Monte Rosa nappe (Western Alps). The protolith and genesis of whiteschist are highly debated in the literature. Whiteschists occur as 10 to 50 m tube-like bodies within the Permian Monte Rosa granite. They consist of chloritoid, talc, phengite, and quartz, with local kyanite, garnet, tourmaline, and carbonates. Whiteschist tourmaline is characterized by an igneous core and a dravitic overgrowth (XMg > 0.9). The core reveals similar chemical composition and zonation as meta-leucogranitic tourmaline (XMg = 0.25, δ18O = 11.3–11.5‰), proving their common origin. Dravitic overgrowths in whiteschists have lower oxygen isotope compositions (8.9–9.5‰). Tourmaline in metagranite is an intermediate schorl-dravite with XMg of 0.50. Oxygen isotope data reveal homogeneous composition for metagranite and meta-leucogranite tourmalines of 10.4–11.3‰ and 11.0–11.9‰, respectively. Quartz inclusions in both meta-igneous rocks show the same oxygen isotopic composition as the quartz in the matrix (13.6–13.9‰). In whiteschist the oxygen isotope composition of quartz included in tourmaline cores lost their igneous signature, having the same values as quartz in the matrix (11.4–11.7‰). A network of small fractures filled with dravitic tourmaline can be observed in the igneous core and suggested to serve as a connection between included quartz and matrix, and lead to recrystallization of the inclusion. In contrast, the igneous core of the whiteschist tourmaline fully retained its magmatic oxygen isotope signature, indicating oxygen diffusion is extremely slow in tourmaline. Tourmaline included in high-pressure chloritoid shows the characteristic dravitic overgrowth, demonstrating that chloritoid grew after the metasomatism responsible for the whiteschist formation, but continued to grow during the Alpine metamorphism. Our data on tourmaline and quartz show that tourmaline-bearing white-schists originated from the related meta-leucogranites, which were locally altered by late magmatic hydrothermal fluids prior to Alpine high-pressure metamorphism.

Abstract We report on the occurrence of a new high-pressure Ca-Al-silicate in localized shock melt pockets found in the feldspatic lunar meteorite Oued Awlitis 001 and discuss the implications of our discovery. The new mineral crystallized as tiny, micrometer-sized, acicular grains in shock melt pockets of roughly anorthitic bulk composition. Transmission electron microscopy based three-dimensional electron diffraction (3D ED) reveals that the CaAl4Si2O11 crystals are identical to the calcium aluminum silicate (CAS) phase first reported from static pressure experiments. The new mineral has a hexagonal structure, with a space group of P63/mmc and lattice parameters of a = 5.42(1) Å; c = 12.70(3) Å; V = 323(4) Å3; Z = 2. This is the first time 3D ED was applied to structure determination of an extraterrestrial mineral. The International Mineralogical Association (IMA) has approved this naturally formed CAS phase as the new mineral “donwilhelmsite” [CaAl4Si2O11], honoring the U.S. lunar geologist Don E. Wilhelms. On the Moon, donwilhelmsite can form from the primordial feldspathic crust during impact cratering events. In the feldspatic lunar meteorite Oued Awlitis 001, needles of donwilhelmsite crystallized in ~200 mm sized shock melt pockets of anorthositic-like chemical composition. These melt pockets quenched within milliseconds during declining shock pressures. Shock melt pockets in meteorites serve as natural crucibles mimicking the conditions expected in the Earth's mantle. Donwilhelmsite forms in the Earth's mantle during deep recycling of aluminous crustal materials, and is a key host for Al and Ca of subducted sediments in most of the transition zone and the uppermost lower mantle (460–700 km). Donwilhelmsite bridges the gap between kyanite and the Ca-component of clinopyroxene at low pressures and the Al-rich Ca-ferrite phase and Ca-perovskite at high-pressures. In ascending buoyant mantle plumes, at about 460 km depth, donwilhelmsite is expected to break down into minerals such as garnet, kyanite, and clinopyroxene. This process may trigger minor partial melting, releasing a range of incompatible minor and trace elements and contributing to the enriched mantle (EM1 and EM2) components associated with subducted sedimentary lithologies.

Mineral resources serve as the foundation of prosperity for any country or community. However, the process of prospecting and exploring these resources is time-consuming and involves financial risks. It requires the combined expertise of both geoscientists and mining engineers, encompassing academic knowledge and professional skills. In this research, we provide an overview of the mineral resources within the Gandaki province of Nepal and evaluate their present status. The main objective is to examine the current status and potential of mineral resources in the province. To achieve this, we extensively utilize available reports, journal articles, and online sources. We gather both primary and secondary data on mineralization. Additionally, we systematically list the potential locations of all documented mineral resources within the Gandaki province, along with their GPS coordinates. Based on the current geological and mineralogical investigations, as well as our understanding of the province’s mineral resources, we identify ten minerals or mineral groups with potential economic value: iron, copper, uranium, tourmaline, syenite, thermal springs, limestone, dolomite, slate, and meta-basic rocks like amphibolite. We strive to provide geological evidence and context for supporting the presence of these minerals.
 In general, iron mineralization is observed as sedimentary deposits, exhibiting a syngenetic nature. Many copper ores are hydrothermally deposited originating from the underlying meta-basic rocks like amphibolite. The region is also known for its abundance of gemstones, including quartz crystals, garnet, kyanite, and tourmaline. These minerals are concentrated in the vicinity of the Main Central Thrust zone and its surrounding areas. Moreover, the province has significant potential for high-quality dimension stones for flooring, roofing, and pavements such as quartzite, slate, phyllite, schist, granite, and gneisses. Additionally, there are ample opportunities for the extraction of construction materials like sand and gravel from the river terraces and natural rock outcrops. Nevertheless, a systematic study focused on prospecting, exploration, and utilization of these potential and possible mineral resources is imperative for an accurate economic evaluation. To achieve this, the provincial government must develop plans and policies to facilitate the development of its own mineral resources. Furthermore, establishing strong collaboration between professionals and academia is crucial to make well-informed investments in the mineral sector. Considering the present status of minerals, the Gandaki province of Nepal holds promising prospects for harnessing its mineral resources for sustainable development.