How to Recognize Vaseline Glass

Identify Vaseline glass with one tried-and-true method: see if it glows! Vaseline glass, initially made before World War II, is unique due to an added ingredient: uranium. It is this critical uranium content that makes Vaseline glass glow when placed under an ultraviolet light. Even the flash of a camera can potentially capture it.

Darken the room and use a blacklight. The color of the glow is quite important. True Vaseline glass will fluoresce as a bright green. The glow in and of itself does not necessarily classify the piece as Vaseline glass. Attempts to add other materials, namely iron, to get the glow can render close results but fail to get that truly brilliant green under UV rays.

Analyze the color of the glass as carefully as the UV glow. While the glow of Vaseline glass under a blacklight should be green, the same is not necessarily true of the glass itself. Older Vaseline glass will have a yellowish to yellow-green color. Some very early pieces are almost clear with a yellow tint or show both yellow and green hues. Green Vaseline glass (such as the one in the photo) are usually Depression glass pieces, again reintroduced in the 1950's when iron was added. While it certainly has its attractors, many collectors find it be second rate to genuine Vaseline glass.

Use your knowledge of color as a tool in judging the age of a piece. If you are at an antique store, ask if a UV light is available if you are still unsure. If your antique dealer cannot give you a date, manufacturer or a blacklight test, it is probably better to pass on the piece unless you love it enough to keep it regardless if it is Vaseline glass. .

Familiar yourself with the many color variations of Vaseline glass. Certainly, the more you study and examine these beautiful items, the more familiar you will become with their appearance, characteristics and probable age. A few online places to begin educating yourself on the particulars of Vaseline glass pieces include the antiques and vintage collectibles at Ruby Lane, Inc., and Valentine Antique Gallery. These are reputable online venues for collectors and buyers alike.

Value a piece of Vaseline glass based on your intention for the piece. As a glass collector, what you love has a different value than what you may purchase for potential profit. While Vaseline glass that pre-dates World War II might have a higher monetary value, many collectors prefer the green of the post-Depression glass. A few glass manufacturers, including Boyd Crystal Art Glass and Fenton Glass, continue to make Vaseline glass, although the ingredients have become more difficult and expensive to obtain. Prices for Vaseline glass in the collector's market clearly reflect the decreased production and continued high demand.