Cube 25x25x25 mm of uranium glass.
These Uranium cubes contain about 1% Uranium which is added to the glass in the molten process. Because of the Uranium in the glass the marbles glow bright under Black Light also known as Ultraviolet Light (UV).
These cubes are completely safe to handle.
If you can find the producer of fluorescent lamp/ tube, do not hesitate to contact us.