| quartz crystal mostly includes amethyst, smoky quartz and yellow quartz. On the bases of heating up amethyst, smoky quartz and yellow quartz; observing the change of their color; determining their absorbency and drawing the absorbency curve in different temperature and on the bases of the results of LA-ICPMas, we discussed the stability of the color centers in quartz crystal.(1) colored crystal can change a color by heat treatment method. color keep stability after changing a color. The temperature is about 500℃when the amethyst changes into colorless and about 550℃changes into light yellow quartz; The color of nature yellow quartz stabilizes when heating up. The color of smoky quartz gradually shallow and stabilize as the temperature rises.(2) The fault of construction which caused by the transition elements Al, Fe, Ti, isomorph replace Si affected the color and stability of colored crystal. The cause of Amethyst mainly relates with the Fe3++O- heart. And in the amethyst the Fe3++O- heart is unstable as heating up. The heating can eliminate the Fe3++O- heart. The temperature which change the color possibly relate with Fe content in amethyst; The color of yellow crystal mainly relates with Fe3++O- and Al3++O- heart. In the smoky crystal, Al3++O- heart cannot cause the quartz to have the color; The Ti is the main causes which have the quartz the smoke color.
|
PDF Full Text Request