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 metamict grains are more discordant than the clear grains, although both types were highly abraded.
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.
Cavities filled with pink beidellite-montmorillonite and metamict pyrochlore-group minerals also occur within the core.
Euhedral topaz, amazonite, and smoky quartz crystals as well as ovoid masses of metamict plumbopyrochlore (and related species) may be found in clay-filled cavities.
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).
Metamict substances, if formed by geological processes, are accepted as mineral species if it can be established with reasonable certainty that the original substance (before metamictization) was a crystalline mineral of the same bulk composition.
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).
Metamict substances, if formed by geological processes, are accepted as minerals if it can be established with reasonable certainty that the original substance (before metamictization) was a crystalline mineral of the same bulk composition.
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.