翡翠皮壳上癣的宝石矿物学研究.doc

翡翠皮壳上癣的宝石矿物学研究 【中文摘要】翡翠是珍贵的玉石品种,有“玉石之王”的美称,纯正冶艳的绿色具有很高的价值。翡翠原石或皮壳上出现的大小不同、外形各异的玄色或深绿色印记称之为癣。固然翡翠中的癣不受大众欢迎,然而其产出形态对却翡翠内部的绿色有着重要的指示意义。作者在前人研究的基础上,运用偏光显微镜、电子探针、X射线衍射、红外光谱、拉曼光谱、扫描电镜等先进的测试手段,对翡翠皮壳上癣的矿物组成及其结构特征进行了具体的研究,并对翡翠皮壳上的癣与其内部绿色之间的关系进行了深进的探讨。研究结果显示癣的矿物组成主要是角闪石族矿物,大多数角闪石属于钠-钙质和钠质角闪石。扫描电镜下观察癣的结构致密,颗粒呈短柱状、纤维状。根据薄片观察对角闪石的成因进行探讨,将角闪石的成因大致分两种。癣和绿的关系大致分为“癣吃绿”和“癣喷绿”。利用“癣吃绿”可以根据翡翠的质地和癣的外形来猜测原石中的绿色。本文尝试从角闪石的晶体结构进手来解释“癣喷绿”现象。这一现象可能是由于铬离子只能占据M2位,很难进进角闪石的晶体结构内。在文章中还总结了癣对翡翠价值的影响,大多数人都以为是负面的,影响翡翠的定名和价值;实在癣对翡翠还有更多的正面影响首先增加翡翠价值,其次为推测翡翠的成因提供有利证据,最后对判定原石也有一定帮助作用。论文在研究翡翠结构时对市面上“起荧”现象的翡翠进行了深进的讨论,以为“起荧”与加工外形有一定关系、抛光对“起荧”也有很大影响,与翡翠的结构存在很大的关系,实验量得矿物颗粒大小基本在0.05-0.14mm范围内。; 【Abstract】 As the king of jade, Feicui is one of the most delighted and profitable jade. Green Feicui is most valuable. The different size and shape of balck and dark green imprint on the weathering crust of the Feicui raw material is named tinea. The tinea is undesirable, but its output and sharp has important indications to the green deep in Feicui. Based on the preresearch, the author study the tinea’s composition and structure by Microscope, EMPA, XRD, FITR, Ramman, SEM means in this ***.The result implies that the tinea is composed of amphibole, most belongs to sodic and sodic-calcic amphibole. The structure of tinea is compact observed from SEM. Mineral grain is prismy and fibrous. Based on the observation from Microscope, the cause of the ation of amphibole is discussed, and can be divided in two groups. The relationship of tinea and green can be described as‘tinea ate green’and‘tinea sprayed green’. We can predicate the green of Feicui according the texture of Feicui and the shape of tinea. Based on the crystal lattice of amphibole, the phenomena‘thnea sprayed green’can be explained as the Cr3 can only occupy the position of M2 and can not occupy the other position in the crystal lattice.“glimmering”FeiCui has a high value, but fewer researches related to this topic have been conducted for past few years through detailed literature review. In this ***, the optical principle and cutting s are studied by using the texture of Feicui. The results shown that the necessary factors of“glimmering”FeiCui ation1. globoidal cutting or globoidal cutting partly; 2. perfect polishing; 3. Basic mineral particles in the 0.05 to 0.14 mm range; 4. Polycrystalline quality aggregates.