Rare Hydrated Magnesium Carbonate Minerals Nesquehonite and Dypingite of the Obnazhennaya Kimberlite Pipe, in the Yakutian Kimberlite Province

The result of a complex mineralogical study of the first discovery of the rare hydrated magnesium carbonate minerals of Nesquehonite and Dypingite in the Obnazhennaya kimberlite pipe (of the Yakutian kimberlite province) is presented. The methods of X-ray phase analysis, electronic microscopy, and Raman spectroscopy have established that the main minerals of the samples found in the form of white crust on a small area of rock outcrop of kimberlite breccia are hydrated carbonates: Nesquehonite is MgCO3•3H2O, Dypingite is Mg5(CO3)4(OH)2•5H2O. The formation of Dypingite over Nesquehonite was shown using Raman imaging for the first time. Nesquehonite is represented as aggregates consisting of chaotically oriented prismatic crystals or kidney-shaped formations. Dypingite in the examined samples appears less frequently as rose-shaped aggregates formed from lamellar crystals. It is assumed that the formation of rare carbonates of the Obnazhennaya kimberlite pipe is mainly the result of the weathering of silicates, formation of mineralized solutions, and their subsequent crystallization, including the capture of CO2 from the air

Determination of boron at the geologicalsamples by atomic emission spectroscopy with using two-jet arc plasmotron

Приведены результаты определения бора в геологических пробах атомно-эмиссионным спектральным методом с применением в качестве источника возбуждения спектров дугового двухструйного плазмотрона. Показано, что модернизация спектрографа ДФС458С и применение многоканальных анализаторов МАЭС позволяет проводить определение бора по группе аналитических линий, что повышает достоверность результатов анализаIn the paper is considered of determination of boron at geological samples by atomic emission spectroscopy with using two-jet arc plasmotron in the capacity of excitation source of spectrums. The modernization of spectrograph DFS-458 and application multichannel analysers MAES gives possibility of boron determination over groups of analytical lines and increases reliability of analysis results

Determination of Ore Contents of Rare Earth Elements in Geological Samples by Atomic Emission Spectrometry with Arc Two-Jet Plasmatron

В работе приведены результаты определения рудных содержаний редкоземельных элементов (РЗЭ) в геологических образцах методом атомно-эмиссионной спектрометрии с дуговым двухструйным плазматроном, позволяющей проводить анализ твердофазных образцов в виде мелкодисперсных порошков. Изучался образец ниобий-редкоземельной руды, отобранный на участке Буранный Томторского месторождения (Арктическая Сибирь, Россия). Результаты анализа по всем РЗЭ, за исключением Tb, Ybи Lu, согласуются с данными ИСП-МС‑анализа. Показано, что использование одновременно нескольких аналитических линий при определении РЗЭ значительно повышает точность определения и достоверность результатовThe paper presents the results of determination of the ore contents of rare earth elements (REE) in geological samples by atomic emission spectrometry with arc two-jet plasmatron, which allows to analyze solid-phase samples asa fine powders. We studied a niobium-rare earth ore sampled at the Buranniy site of the Tomtor deposit (Arctic Siberia, Russia). The results for all REEs, except for Tb, Yb and Lu, are consistent with the ICP-MS data. It is shown that the use of several analytical lines at the same time in the determination of REE significantly increases the determination accuracy and reliability of the result