Question: What Is Uranium Glass or Vaseline Glass?
Uranium glass fluoresces with a characteristic green light under ultraviolet or black light. Uranium glass is sometimes known as Vaseline glass because its greasy appearance is akin to that of petroleum jelly. Here's a look at what uranium glass is and how it is used.
Answer: Simply put, uranium glass is glass that contains uranium. Usually uranium is added to glass before it is melted as a diuranate oxide. Modern uranium glass is about 2% uranium, by weight, although some 19th century pieces contain as much as 25% uranium. The glass comes in shades of yellow and green, although other colors are possible if additional metals have been added. A Geiger counter will register radioactivity from some uranium glass, although it is not sufficiently radioactive to pose a health hazard. Uranium glass is called "Vaseline glass" because the milky, greasy appearance of the glass resembles that of petroleum jelly.