Crystal Structure Studies of Common Rare Earth Bearing Minerals

稀土元素在矿物中的基本晶体化学行为尚不清楚。在原子排列未知或特征不明显的矿物中，最常见的含稀土矿物包括：1)氟碳铈矿，这是最丰富的含稀土矿石矿物，及其伴生的稀土氟碳酸盐；2)常见的稀土（PO4）“二晶体”，莫独居石和xenotime，以及3)高硅独居石，特别令人感兴趣，因为取代基Si可能在控制独居石的稀土化学中起重要作用。在提交这份报告之前，已经进行了广泛的努力，以获得这些矿物的高质量标本，以便对其相进行高精度的晶体结构分析。初步的薄膜研究证明了晶体的高质量，并最终保证了晶体结构研究的成功。这些研究结果将有助于阐明稀土在最常见的含稀土矿物中的晶体化学行为。

The fundamental crystal chemical behavior of REEs in minerals is not well understood. Among those minerals whose atomic arrangements are unknown or poorly characterized are the most common REE-bearing minerals, including 1) bastnaesite, the most abundant REE-bearing ore mineral, and its associated REE fluorcarbonates; 2) the common REE (PO4) "dimorphs", moazite and xenotime, and 3) high-Si monazite, of particular interest because substituent Si may play an important role in controlling the REE chemistry of monazites. Preliminary to this submission an extensive effort has been undertaken to obtain high quality specimens of these minerals in order to undertake high-precision crystal structure analysis of the phases. Preliminary film studies attest to the high quality of the crystals and ultimately assure success in the crystal structure studies. The results of these studies will help to elucidate the crystal chemical behavior of the REEs in the most common REE-bearing minerals.