A pristine Small Cabinet fluorite specimen like this piece from the Rogerley Mine is always a treat, and this one is special.  The crystals are super gemmy and almost completely transparent (there are none of the white bubble inclusions that are so common on Rogerley material).  The crystal faces are wet-look lustrous and flashy, and are completely transparent so you can look right inside the penetrating twin crystals.  In addition to the usual long wave fluorescence there is a bit of daylight fluorescence visible on the edges and corners.