Things You'll Need
Instructions
Take a look at the color. It should be in the yellow to green spectrum.
View the glass under a black light. The uranium in the glass will fluoresce green under ultra-violet light. A black light pen is a handy tool for identifying Vaseline glass.
Use a Geiger counter. Uranium is radioactive and a sensitive meter will pick up the trace amounts of radioactivity. Don't worry about the radiation. The trace amounts of radiation found in Vaseline glass are not harmful.