Combined influences of iron-oxides and micropores on reddish coloration of alkali feldspars in granitic rocks
Combined influences of iron-oxides and micropores on reddish coloration of alkali feldspars in granitic rocks
复制标题
铁氧化物和微孔对花岗质岩石中碱长石红色着色的综合影响
DOI：
10.5575/geosoc.2019.0025
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Kohno
中科院分区：
文献类型：
--
作者：
S. Nakano;K. Makino;Izumi Yoshida;K. Maniwa;K. Sawada;Fuko Sakashita;T. Kohno
用扫描器和个人计算机系统测定了4种花岗岩碱长石的国际颜色参数（L*、a*和b*），显示出连续的红色变化。双筒显微镜下观察到微红颗粒和微孔。拉曼光谱分析结果表明，4种长石样品中常见的红色颗粒为赤铁矿，g175长石样品中常见的红色颗粒为磁铁矿。利用电子探针测图评估了氧化铁颗粒和微孔的分布，并通过图像处理获得了它们在长石中的面积百分比。结果表明，赤铁矿和微孔的粒度分布和数量密度控制了碱长石的红色变化，外加磁铁矿的存在等影响因素。
The international color parameters (L*, a*, and b*) of four granite alkali feldspars, determined by a new method using a scanner and personal computor system show a successive variation of reddish colors. Small reddish particles and whitish micropores were observed using a binocular microscope. Raman spectroscopy showed that the common reddish particles are hematite in all four feldspar samples, and showed maghemite in the G 175 feldspar. Distributions of Fe-ox-ide particles and micropores were assessed by electron microprobe mapping, and their area percentages in the feldspars were obtained using image processing. The results suggest that the size distribution and number density of both hematite and micropores control the reddish color variation in the alkali feldspars, with some additional influencing factors such as the presence of maghemite.