Those of us who are fortunate enough to be able to attend at least one major mineral show will probably have experienced entering a room or seeing a stand overflowing with rose quartz spheres and cabochons of many sizes, all displaying six-rayed stars of varying degrees of definition. The intensity of the rose color also varies over a wide range. The factors that determine the price of the spheres generally come down to the size of the sphere, the depth of its rose color, and the sharpness and/or visibility of the star. The origin of stars in semitransparent to translucent gem materials is well known. The classic explanation is that these stones contain microscopic inclusions of a fibrous mineral that was exsolved within the crystal as it cooled, and that the orientation of these fibers is not random but is controlled by the crystal's structure. Thus the fibers are aligned in specific directions within the crystal, and these directions, one might say, are dictated by the crystal. Reflections from these fibers are what produce a star.
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