Uranium glass

The collection contains dozens of glass objects viewed under ultraviolet light. Uranium oxide was used to colour glass. The additive gave it a yellow or yellow-green appearance, while other ingredients could modify the final colour. Here, uranium is part of a glassmaker's product. Its role differs from that in the ore seen during the geological part of the visit: it was used to give a finished object a particular appearance.

Under UV light, typical uranium glass emits green light. This phenomenon is called fluorescence and results from the interaction of the illumination with uranium compounds in the glass. The transparent yellow or yellow-green variety is sometimes called Vaseline glass. The name describes its appearance, not the presence of petroleum jelly in its composition.

Uranium-containing glass can be transparent or opaque. Yellow-green glass can also be made using additives that contain no uranium. Its glow should not be confused with visible radioactive emissions. UV lighting reveals an optical property of the material; it does not measure its radioactivity. The collection therefore invites two distinct comparisons: an object's appearance under different lighting and the relationship between its colour and the additive used.