Xenotime dating. Xenotime

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XENOTIME

xenotime dating

Une géothermomètre fondé sur le couple monazite- Ce — xénotime- Y , développé pour les roches métamorphiques, donne une température relativement élevée pour la formation du xénotime- Y , dépassant 450°C. All localities listed without proper references should be considered as questionable. Later, Glocker 1831 introduced the name Ytterspath. Uniquely, at Lofdal, Namibia, xenotime- Y occurs in many carbonatite dykes. Gems: Their sources, descriptions and identification 5th ed.

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Xenotime

xenotime dating

While xenotime may contain significant amounts of thorium or uranium, the mineral does not undergo like or zircon would. It is considered brittle and its is white. This stone is widely appreciated in Japan for its ornamental value. Xenotime is also known to be : It may form as minute grains or as extremely thin less than 10 coatings on detrital zircon grains in siliciclastic. An interesting, strongly fluorine-enriched xenotime- Y , was described from Madeira pluton, Pitinga, Brasil. It was coined by French mineralogist as a rebuke of another scientist, Swedish chemist , for the latter's premature claim to have found in the mineral a new later understood to be previously discovered yttrium.

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XENOTIME

xenotime dating

A recent find of As-rich xenotime- Y , accompanied by - solid solution, in a silicified Agathoxylon wood is described by Matisová et al. Xenotime has two directions of perfect prismatic and its is uneven to irregular sometimes splintery. The Canadian Mineralogist ; 46 4 : 861—877. The , , and , as well as metal elements such as and all replacing yttrium are the expressive secondary components of xenotime. Dysprosium is usually the most abundant of the even-numbered heavies, and holmium is the most abundant of the odd-numbered heavies.

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Xenotime

xenotime dating

Small tonnages of xenotime sand are recovered in association with Malaysian tin mining, etc. Occasionally, are also cut from the finer xenotime crystals. Xenotime was first described for an occurrence in , in 1824. Dans la séquence paragénétique, le xénotime- Y apparait à la fin du cycle magmatique et sûrement au cours du stade hydrothermal. Ces caractéristiques seraient importantes pour expliquer la production du xénotime- Y à Lofdal. It mantles and replaces zircon in calcite carbonatite and also occurs as aggregates in ankerite carbonatite, aggregates associated with hematite, and crystals associated with monazite- Ce and synchysite- Ce in highly oxidized iron-rich calcite carbonatites. Other notable localities include: and , Norway; , and , ; and , , , and ,.

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Helium Diffusion in Natural Xenotime

xenotime dating

These features are most important in controlling the production of xenotime- Y at Lofdal. Citation Frances Wall, Vistorina N. The importance of these diagenetic xenotime deposits in the of sedimentary rocks is only beginning to be realised. Le xénotime- Y est un minéral accessoire répandu dans plusieurs sortes de roches ignées et métamorphiques, mais il est rarissime dans les carbonatites. Its , which may be vitreous to resinous, together with its crystal system, may lead to a confusion with ZrSiO 4 , the latter having a similar crystal structure and with which xenotime may sometimes occur. Associated minerals include and other micas, minerals, quartz, zircon, certain , , , , , and. Xenotime is used chiefly as a source of yttrium and heavy metals dysprosium, ytterbium, erbium and gadolinium.

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Xenotime

xenotime dating

Elle confirme que la formation du xénotime- Y est directement liée à la cristallisation de la carbonatite; la date concorde avec les dates déjà publiées pour les syénites de Lofdal et Oas. The paragenetic sequence places the xenotime- Y at the end of magmatic activity and certainly into the hydrothermal stage. There is no reaction under light. It forms a solid solution series with 4 and therefore may contain trace of , as well as and. Xenotime has a variable : It may be prismatic stubby or slender and elongate with dipyramidal terminations, in radial or granular aggregates, or rosettes. The lightest lanthanides are generally better represented in monazite while the heaviest lanthanides are in xenotime.

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Xenotime

xenotime dating

A new discovery of gemmy, colour change brownish to yellow xenotime has been reported from and been found in. A Lofdal, en Namibie, on le trouve dans plusieurs filons de carbonatite. Struck out - Mineral was erroneously reported from this locality. The name xenotime was finally coined by the French mineralogist François Sulpice Beudant 1832 in his 2. .

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XENOTIME

xenotime dating

Xenotime- Y was found by the Norwegian mineralogist Nils Otto Tank 1800-1864 and first described by the Swedish chemist Jøns Jacob Berzelius in 1824 as Phosphorsyrad Ytterjord from a granite pegmatite at. The P or phosphate analogue of and. Due to uranium and thorium impurities, some xenotime specimens may be weakly to strongly. Discovered in 1824, xenotime's type locality is Hitterø , , ,. Xenotime is with pink, yellow or yellowish brown seen in the extraordinary ray and brownish yellow, grayish brown or greenish brown seen in the ordinary ray.

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Helium Diffusion in Natural Xenotime

xenotime dating

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XENOTIME

xenotime dating

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