Have you ever purchased Vaseline Glass online only to find that what you received was not Vaseline Glass at all? There you were... all excited to open your package; you just couldn't wait to see it under the blacklight. But when you held it under the blacklight, it didn't glow with the vibrant green you were expecting to see.

This guide is meant for both Sellers and Buyers to read:

So many Sellers list their item as Vaseline Glass when they haven't tested the piece they are selling under a UV light. This is usually not a purposeful thing the Seller does, however, it is something the Seller should know to check if he/she is listing an item as Vaseline Glass.

Definition of Vaseline Glass:

Different parts of the world have different definitions for Vaseline Glass, but in the U.S., the basic definition for Vaseline Glass is that 2% Uranium Dioxide (by weight) has been added to the formula as a coloring agent, thereby giving us that lovely yellow color without UV lighting and also a brilliant green fluorescent glow that collectors (me included) can't get enough of when under blacklight.

Uranium Glass is another name for Vaseline Glass. Therefore, if it does not have Uranium in it, it is not Vaseline Glass.

Verification:

Vaseline Glass is verified by using a blacklight in order for the piece to glow from yellow to a vibrant fluorescent green.

Don't be mislead by ads listing the item as Vaseline Glass, just by eyeballing the photo online. Make sure to ask the Seller if the item has been blacklight tested, and also be sure to ask what color the item glowed. Some glass pieces have formulas in which manganese was added instead of Uranium Dioxide. Those particular pieces will glow dimly in peach colors or a faint green (remember, Vaseline Glass glows a brilliant green).

Also some would argue that other glass that glows (Green Depression, etc.) is Vaseline Glass. I will address this point later, but I take on the purist view, that only yellow or yellow-green glass that glows green under UV light is true Vaseline Glass.

What should the collector look for?

Vaseline Glass is a yellow or yellow-green glass piece that turns bright fluorescent green under the blacklight.

Some collectors also collect Green Depression glass which also glows under the blacklight. But, as far as my purist view goes, that is not Vaseline Glass. Green Depression glass has uranium in the formula, but also contains another coloring agent which makes it green. That added ingredient is iron oxide or, in other words, rust.

The Main Question a Buyer Should Ask:

If the item in the ad does not say whether the item glows or if it fails to show any photos in which the item is glowing, a probable question would be...

Has this item been blacklight tested? If so, what color does it glow while under the blacklight?

If the answer to "has it been blacklight tested" is no and the buyer is not willing to show the piece under a UV light (sometimes a Seller does not have a blacklight with which to test the glass), then move on and save your money unless you are 100% sure, by the photo(s) in the ad that it is Vaseline Glass.

If the Seller says that it glows purple, then you know that the piece is just reflecting the purple hue from the UV light and is not Vaseline. If the answer is that it glows orange, peach or any other color than brilliant green, it is not Vaseline Glass.

When purchasing an item that I list here as "not being Vaseline Glass", really that is up to personal taste. I'm sure there are collectors out there who love to collect pieces that glow in different colors. As I am also sure there are a lot of Vaseline collector's out there who collect Green Depression and consider it Vaseline. Again, it's all up to personal taste.

Conclusion:

I've made this guide as short as possible... in doing so, I haven't even touched on the history of Vaseline (or Uranium) Glass. What I hoped to do, however, is to help Sellers to know what they are selling, and also to help Buyers in making purchases. No one wants to buy something online only to find out the item is far from what they expected.

There are some great pieces of Vaseline listed on eBay! All you have to do is know what you're looking for.... opening the package once it gets to you is a very exciting thing!