Перевод названия: ТАШЕЛГИТ CaMgFe2+Al9O16(OH) - НОВЫЙ МИНЕРАЛ ИЗ ИЗВЕСТКОВЫХ СКАРНОИДОВ ГОРНОЙ ШОРИИ
Тип публикации: статья из журнала
Год издания: 2011
Ключевые слова: ташелгит, гидроксид, известковый скарноид, tashelgite, hydroxide, calcium metasomatic rock, new mineral, crystal structure, новый минерал, кристаллическая структура
Аннотация: The new mineral species has been discovered in Tashelginskoye occurrence of calcium skarnoid rocks near mouth of the Tashelga River (Kuznetsky Alatau Mountains, Gornaya Shoria, Russia) and named after the discovery locality. Associated minerals are calcite, hibonite, grossular, vesuvianite, hercynite, magnetite, corundum, perovskitПоказать полностьюe, scapolite, diopside and apatite. The new mineral occurs as prismatic or fine-fibrous crystals up to 1.5-2 mm in length, their parallel growths and felt-like aggregates up to 10 mm in diameter. Tashelgite is translucent up to transparent. Its color is bluish-green, luster vitreous. Dcalc = 3.67 g/cm3. ER spectrum does not contain bands due to OH groups. Tashelgite is biaxial (-), with ? = 1.736(2), ? = 1.746(2), ? = 1.750(2), 2V (meas.) = -20(2)°. Dispersion is strong, r v. Pleochroism: X (blue-green) Y (yellowish-green) Z (almost colorless). Chemical composition (electron microprobe, mean of 5 point analyses, Fe2O3 by the ratio of intensities I(FeK?5)/I(FeK?1) in the X-ray spectrum, H2O was determined as weig ht loss on heating in vacuum up to 1000 °С): CaO 7.98, MgO 6.75, MnO 0.45, FeO 11.32, Fe2O3 1.40, Al2O3 70.70, H2O 1.8(2), total sum 100.40. The empirical formula calculated on 17 O atoms is: H1.27Ca0.90Mg1.06Mn0.04Fe2+1.00Fe3+0.11Al8.80O17.00. The idealized formula is: CaMgFe2+-Al9O16(OH). According to the single-crystal X-ray structural data, tashelgite is monoclinic, pseudo-orthorhombic, space group Pc; unit-cell parameters are: a = 5.6973(1), b = 17.1823(4), c = 23.5718(5) A; ? = 90.046(3)°; V = 2307.5(1) A3, Z =8. The crystal structure of tashelgite is unique and is characterized by the ordering of all cations; Al occupies sites with octahedral and tetrahedral coordination. The cation ordering is confirmed also by IR spectroscopy. The strongest lines of the X-ray powder diffraction pattern (d, к-ЦНЩ) are: 11.79-48 [002], 2.845-43 [061], 2.616-100 [108], 2.584-81 [146], 2.437-44 [163], 2.406-61 [057], 2.202-72 [244]. Type specimen of tashelgite is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. Новый минерал ташелгит CaMgFe2+Al9O16(OH) найден в известковых скарноидах Ташелгинского проявления (северные отроги Кузнецкого Алатау, Горная Шория) в ассоциации с хибонитом, гроссуляром, везувианом, магнетитом, герцинитом, корундом, апатитом, перовскитом, диопсидом и апатитом.
Журнал: Записки Российского минералогического общества
Выпуск журнала: Т. 140, № 1
Номера страниц: 49-57
ISSN журнала: 08696055
Место издания: Санкт-Петербург
Издатель: Федеральное государственное унитарное предприятие "Академический научно-издательский, производственно-полиграфический и книгораспространительский центр Российской академии наук "Издательство "Наука"