Additional data on reevesite and its Co-analogue, as a new member of the hydrotalcite group

作者：Yixiang Song, Hong‐Seok Moon · 发表于：Clay Minerals · 年份：1998 · DOI：10.1180/000985598545480 · 被引用次数：13 · 研究领域：Layered Double Hydroxides Synthesis and Applications、Clay minerals and soil interactions、Crystal Structures and Properties

Abstract Reevesite, the Ni-Fe member of the hydrotalcite group, occurs as a secondary mineral in the serpentinized ultramafic rocks of the Kwangcheon area in Korea, replacing the pecoraitc-magnetite-millerite-polydymite assemblages in small veins lining cracks and fracture zones. Chemical analyses for the reevesites indicate the presence of the Co-analogue of reevesite and the complete solid-solution between Fe 3+ and Co 3+ . The Co-analogue of the reevesite shows the approximate ratio of 3:1 of divalent to trivalent cations, which is in distinct contrast to the comblainite with the ratio of 2:1 reported by Piret & Deliens (1980). The presence of the complete solid-solution phase between Fe 3+ and Co 3+ is confirmed by synthesis at room temperature. On the basis of the results, the Co-analogue of the reevesite should be named as a new member of the hydrotalcite group, and thereby be distinguished from the comblainite. The partial substitutions of SO 2- 4 for CO 2- 3 in the interlayer region might affect the slight increase of the basal spacing in the reevesite. The synthesis performed suggests that the reevesite could be precipitated under either an alkaline or a neutral environment, if carbonate activity is high enough.