| 释义 |
metamict, a. Min.|ˈmɛtəmɪkt|
[ad. Da. metamikt (W. C. Broegger 1893, in Salmonsens Konversationsleksikon I. 743/2), f. Gr. µετα- meta- + µικτ-ός mixed, blended.]
Of a mineral: converted into an amorphous state as a result of the radioactive decay of atoms contained in it. Also applied to the state itself.
1927Phil. Mag. IV. 525 Metamict substances like xeno-time and thorite have probably been formed under very high pressure. 1950Science 24 Mar. 312/2 For materials which are completely metamict, it would be possible to determine only a minimum age. 1965G. J. Williams Econ. Geol. N.Z. xiii. 203/2 He suggested the red colouration occurs only in pegmatites sufficiently old for the transformation of the radioactive mineral to the metamict state. 1970Nature 11 Apr. 147/2 Quartz is thus a ‘metamict’ mineral, like zircon.
Hence ˌmetamictiˈzation, the process of becoming, or state of being, metamict; ˈmetamictness, metamict character.
1952Amer. Mineralogist XXXVII. 142 There has been some speculation as to the reasons for variations in degree of metamictness of different samples of the same mineral. Ibid. 154 More powerful sources of radiation..might prove useful in the study of metamictization. 1966McGraw-Hill Encycl. Sci. & Technol. VIII. 296a/1 X-ray methods do not permit a close estimate of the degree of metamictness. 1970Science 30 Jan. 617/1 The U and Th contents of baddeleyite are quite low, which explains the high transparency and the lack of metamictization. |