首页 理论教育拉长石:彩色宝石与矿物集萃,芬兰产最佳

拉长石:彩色宝石与矿物集萃,芬兰产最佳

【摘要】:拉长石比较常见,属斜长石的亚种。拉长石晶体大多呈板状、柱状,其中具有晕彩的矿物是拉长石的重要宝石品种。宝石级拉长石呈微透明至半透明,玻璃光泽,颜色一般为灰白至灰黑色,伴有红色、蓝色、绿色、黄色晕彩,呈现一种特殊的虹彩闪光。一种商界称作“光谱石”的,具有艳丽的晕彩效应的拉长石主要产自芬兰。

(Labradorite)

拉长石比较常见,属斜长石的亚种。英文名称来自主要产地加拿大的拉布拉多(Labrador)。拉长石晶体大多呈板状、柱状,其中具有晕彩的矿物是拉长石的重要宝石品种。宝石级拉长石呈微透明至半透明,玻璃光泽,颜色一般为灰白至灰黑色,伴有红色、蓝色、绿色、黄色晕彩,呈现一种特殊的虹彩闪光。产生这种光学效应的原因,主要是内部平行板状、细页片状双晶与出熔结构面对入射光产生干涉而成。产地主要有加拿大、美国、马达加斯加和芬兰等。一种商界称作“光谱石”(Spectrolite)的,具有艳丽的晕彩效应的拉长石主要产自芬兰。

·带有晕彩的拉长石晶体

·带有晕彩的柱状拉长石晶体

·拉长石的双晶结构

A member of the plagioclase feldspar group, labradorite is characterized by a type of schiller, or internal glow, known as labradorescence. Labradorescence, which causes the stone to flash different colors as the stone is viewed from different directions,is caused by the diffraction of light through twinned, directional layers. The base color of labradorite is typically gray, blue, white,or colorless. Both Finland and England produce a type of high-quality labradorite called spectrolite that exhibits a higher labradorescence and a wider range of colors than most labradorite.

·金红石针状内含物和钛铁矿板状内含物