Ahhhh....I love Vaseline glass. It comes in a variety of textures and colors, so it is sometimes hard to distinguish true Vaseline/uranium glass. Let me tell you a few things that I have learned over the years.
Some purists will only collect the glass that is yellow in color when viewed with the naked eye. Many will tell you that yellow glass is the only "true" Vaseline/uranium glass. This is a fallacy. Uranium dioxide salts do, indeed, have a yellow color that will turn glass a lovely yellow/gold when added before molding, but green coloring was also added to glass that contained uranium salts, and this creates a beautiful gel-like green color when viewed with the naked eye. This beautiful glass comes in a smooth finish as well as a satin finish, and sometimes it even has light colored accents added. (As with Fenton's hobnail patterns.) "Custard Glass" and "Bohemian Glass" are also glasses that contain uranium dioxide. In some cases uranium glass can also be blue, pink, gold, and even purple!
Uranium glass has been manufactured since the early 18th century, and some think it goes much further back than that! Whitefriar's Glass in England popularized uranium glass in the mid-1830s, and it was manufactured pretty steadily from then until the late 1940s. It was particularly popular during the Victorian era, and found a resurgence in the 1920s. There are a couple of manufacturers in the United States and Czechoslovakia who still make uranium glass, but by and large production has ceased.
There has been a great deal of controversy concerning the health risks involved in owning and using uranium glass. The glass does register as radioactive on a geiger counter, but tests have been done that prove pretty conclusively that there is no danger in such low levels of radiation. It is recommended, however, that you avoid grinding or sanding glass that contains uranium dioxide since it is dangerous to inhale the dust.
Many people ask how to test glass to make sure that it is true uranium/Vaseline. The easiest way to test is to use a small hand-held black light. These can be purchased on eBay at a very modest price, and they're small enough to tuck into a pocket or purse to be used at auctions and sales. Simply shine the black light on the piece of glass, and if it fluoresces green, then it contains uranium. No matter what color the glass is to the naked eye, it will ALWAYS fluoresce bright green if it is true uranium glass. (The higher the uranium content, the brighter it will fluoresce.) There are also quite a few pieces of glass that were made with magnesium oxide, but these will fluoresce bright orange under the black light. (These are also beautiful pieces of glass, and are also antiques. They're just not true uranium glass.) Many hard-core collectors also carry a small geiger counter, but I have never felt that it was necessary to do so.
Uranium/Vaseline glass is a lot of fun to display. We used velcro to discreetly place long black lights in an antique display cabinet. This works best if the cabinet is glassed just on the front, and has medium- to dark-colored wood on the inside back and sides. Put your uranium glass in, turn on the lights and viola! A beautiful display that will amaze your friends!
Good luck collecting this lovely glass, and be sure to check our store for a large selection!
