Издательство: | Книга по требованию |
Дата выхода: | июль 2011 |
ISBN: | 978-6-1326-3969-1 |
Объём: | 88 страниц |
Масса: | 153 г |
Размеры(В x Ш x Т), см: | 23 x 16 x 1 |
High Quality Content by WIKIPEDIA articles! Fergusonite is a mineral comprising a complex oxide of various rare earth elements. The chemical formula of fergusonite species is (Y,RE)NbO4, where RE = rare-earth elements in solid solution with Y. Yttrium is usually dominant (the species fergusonite-(Y)), but sometimes Ce or Nd may predominate in molar proportion (species fergusonite-(Ce) and fergusonite-(Nd)). All the other rare earth elements are present in subordinate amount, and tantalum substitutes for some of the niobium. The mineral has tetragonal crystal symmetry and the same structure as scheelite (calcium tungstate, CaW4), but can be metamict (amorphous) due to radiation damage from its small content of thorium. It is found as needle-like or prismatic crystals in pegmatite. It was named after British Politician and mineral collector Robert Ferguson of Raith (1767 1840)
Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.