Fine example of the reversible photosensitive variety of Sodalite. A translucent, almost colourless cabochon example fashioned for jewellery making or for a gemstone collection. The stone darkens a little upon prolonged exposure to Long Wave Ultraviolet light (LWUV). During exposure it fluoresces a bright pinkish orange and phosphoresces a pale blue colour for a few second once the UV is turned off. Otherwise known as tenebrescence, this phenomenon shows remarkably well in this stone.