How to Identify Vaseline Glass

Examine the color of the glass. The color should range from yellow-green to green in natural light. If the glass is more of a true green, it most likely had an additional colorant added to it, probably iron. Many collectors do not consider this green glass to be true Vaseline glass and classify it in the less desirable category of Depression glass.

Place the glass under ultraviolet light (a black light). This is the only universally accepted method used to properly identify Vaseline glass. When placed under a black light, the uranium in authentic Vaseline glass will create a bright fluorescent green glow. There are other types of glass that may glow green as well under a black light but will probably be a different color in daylight, such as green Depression glass or blue-colored glass. Vaseline glass will also have a slight green glow in sunlight.

Inspect the color of the glass carefully when it is under the black light. Although the color of the glass generally should be bright green under the light, older Vaseline glass will have a yellow to yellow-green color. A number of very early pieces may be practically clear with a yellow tint or they may display yellow and green tones.

Consult published pictures of verified Vaseline glass shown both in natural light and under a black light. Compare the photos with your piece. Excellent examples with photos can be found at the websites "valentineantiquegallery" and "rubylane" (see Resources).