Tenebrescence
（重定向自Tenebrescent）
![Hackmanite before (top) and after (bottom) exposure to UV](/Images/godic/202502/15/Hackmanite_before_and_after_exposure_to_UV3956.jpg")
Tenebrescence, also known as reversible photochromism, is the ability of minerals to change colour when exposed to sunlight. The effect can be repeated indefinitely, but is destroyed by heating.
Tenebrescent minerals include hackmanite sodalite, spodumene and tugtupite.