metamict


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metamict

[′med·ə‚mikt]
(mineralogy)
Of a radioactive mineral, exhibiting lattice disruption due to radiation damage while the original external morphology is retained.
References in periodicals archive ?
The study covers the comparative analysis of sands of different origins (United States, Australia, and South Africa) with the aim of characterizing the type and the extension of the regions constituting the metamict state in untreated materials from geographically distinct areas as well as the modifications observed as a consequence of the industrial milling process and the thermal treatment (annealing) in the production line.
This interaction has been observed in fully metamict zircons [19, 29].
The metamict grains are more discordant than the clear grains, although both types were highly abraded.
X-ray powder-diffraction results show the mineral to be metamict.
(1961) Ekanite, a new metamict mineral from Ceylon.
(2001) Polyakovite-(Ce), [(REE,Ca).sub.4](Mg,[Fe.sup.2+])[([Cr.sup.3+],[Fe.sup.3+]).sub.2][(Ti ,Nb).sub.2][Si.sub.4][O.sub.22], a new metamict mineral species from the Ilmen Mountains, southern Urals, Russia: mineral description and crystal chemistry.
The mineral is metamict and the unit cell parameter and the X-ray powder diffraction data were obtained after heating at 700[degrees]C for four hours.
The mineral appears to be metamict (Cotelo Neiva and Correia Neves, 1960).
Minor minerals include hematite, metamict plumbopyrochlore grading to other members of the pyrochlore group showing distinct alteration haloes, and zircon plus thorite near the contacts.
Such substances can be divided into two categories: amorphous (substances that have never been crystalline and do not diffract), and metamict (those that were crystalline at one time, but whose crystallinity has been destroyed by ionizing radiation).
Such substances can be divided into two categories: amorphous (substances that have never been crystalline and do not diffract X-rays or electrons) and metamict (those that were crystalline at one time, but whose crystallinity has been destroyed by ionizing radiation).
Weathered, irregular, metamict nodules and rounded, elongated crystals of red-brown color and glassy to waxy luster were found on the dumps shortly after the mine ceased operating in 1981.