BACKGROUND The needle-like inclusions in rose quartz are considered to be rutile or dumortierite, and their orientation is related to the c-axis. However, there is no consensus on this statement.
OBJECTIVES To find out the distribution characteristics and component of needle-like inclusions in rose quartz using multiple methods.
METHODS Four starlight powder crystals containing acicular inclusions were selected, observed and tested using gemological Microscopes, Laser Raman Spectroscopy, and Ultraviolet-visible Absorption Spectroscopy.
RESULTS The Raman experiments show that the characteristic vibration peaks 949 cm-1 and 999 cm-1 of needles match those of dumortierite and the needle-like inclusions are dumortierite or minerals similar to dumortierite. Magnification examination reveals that the inclusions are approximately 0.5 μm in diameter, with a length of up to millimeters, a near-directional distribution, and a convergent shape as a whole. They can be roughly divided into three groups at certain positions. The needle-like inclusions in the same group are distributed approximately parallel. The three blue-ray lines of six-pointed starlights intersected three-dimensionally, and no obvious three-dimensional symmetry was observed. It was not directly related to the crystallization habit of crystals.
CONCLUSIONS It is believed that blue-ray stones form inclusions first and are captured during the growth of crystals. The UV-visible Spectroscopic Spectrum only absorbs the pink dumortierite, indicating that a large number of pink dumortierite inclusions contribute to the pinkness of the pink crystal.