Everything you need to know about thrifting Uranium Glass

For thrifters, few items spark as much joy as uranium glass. Especially that joyous feeling of spotting a piece *in the wild* priced below its true value. We respect the game of resellers (and hey, might even be resellers ourselves!) but there is an unmatched pride to finding a piece for a dollar at a yard sale or getting a nice Fenton compote for $5 at an estate sale.

With its distinctive green glow under ultraviolet light, Uranium glassware has captivated thrifters for decades. But what exactly is uranium glass, and how can you identify and collect it safely? Read on for a comprehensive guide.

how to identify uranium glass

What is Uranium Glass?

Uranium glass, also known as vaseline glass due to its yellow-green tint, was produced from the 1830s to the 1940s. It contains trace amounts of uranium oxide, which gives the glass its unique colour and fluorescent properties under UV light.

How to Identify Uranium Glass

uranium glass glowing

Using a UV light

The most reliable way to identify uranium glass is to check if it glows when exposed to a UV blacklight in a darkened room. This fluorescence is unmistakable and caused by the uranium oxide additives. For this reason, it is recommended to carry around a small UV flashlight when you go thrifting.

Using a Geiger Counter

Another reliable method is to use a Geiger counter. You’d use a Geiger counter to check for uranium glass because it can detect the low levels of radiation that uranium glass emits. The Geiger counter will let you know if the glass is actually uranium glass by picking up on this radiation. It’s a straightforward way to confirm that your glass piece contains uranium without any guesswork.

Colours Can Be Deceiving

However, don’t rely solely on colour to identify uranium glass. Its tones can range from pale yellowish hues to deep greens. Some non-uranium glass may appear similar under normal light.

How to Tell Without a Blacklight

Identifying uranium glass without UV light is extremely difficult, if not impossible. The myth that it has a distinctive “greasy” or “slimy” feel has been debunked. Your best bet is to examine the piece under incandescent and natural light, looking for the telltale green, yellow, or olive branch tones that could indicate uranium content. But a blacklight test or using a Geiger counter are truly the only ways to confirm.

Collecting Uranium Glass: Tips and Tricks

  • Use a quality UV blacklight to properly identify pieces when thrifting.
  • Learn to recognize popular patterns like Grape, Strawberry, and Coin Spot from makers like Fenton.
  • Inspect closely for damage like cracks, chips, or dullness which diminish value.
  • Start a themed collection focused on a particular pattern, colour, or type of piece.
  • Handle with care and avoid cleaning with abrasive materials that can scratch.
  • Display proudly but away from direct sunlight to prevent colour fading.

Is Uranium Glass Dangerous?

Uranium glass is generally safe to use for eating and drinking. The radioactive particles in uranium glass are suspended within the glass, so they don’t give off much radiation. The real concern is with uranium-glazed ceramics, which can be dangerous and should be avoided for food use. If your uranium glass is chipped or broken, it’s best not to use it to avoid any risk of ingesting small glass particles. You also shouldn’t use knives or abrasive materials on it, as they could break off tiny shards. Otherwise, uranium glass is one of the safer radioactive materials you might come across and can be used without worry.

Is Uranium Glass Valuable?

Like any antique glass, the value of uranium glass depends on several factors:

  • Rarity: Certain patterns and manufacturers are harder to find, making them more valuable
  • Condition: Pieces in pristine condition with no chips or cracks are more valuable
  • Desirability: Popular patterns and styles from respected makers are in higher demand

In general, common uranium glass bowls or vases in good shape can fetch $20-100, while rare or exceptional pieces can sell for hundreds or even thousands of dollars.

Blue Uranium Glass

While most thrifters are familiar with the yellow-green hues of classic uranium glass, there is an even rarer and more mesmerizing variety – blue uranium glass. This exquisite glassware exhibits a stunning blue or cyan colour when exposed to ultraviolet light. The blue tint is achieved by adding cobalt compounds during manufacturing, in addition to the uranium oxide that gives it its fluorescent properties. Blue uranium glass pieces are highly coveted for their distinct beauty and scarcity. From vases and bowls to decorative figurines, these blue-glowing treasures are true prizes for any serious uranium glass collection. Finding authentic blue uranium glass can be challenging, but makes the hunt all the more rewarding for dedicated thrifters.

Vaseline Glass vs Uranium Glass

While the terms “vaseline glass” and “uranium glass” are often used interchangeably, there is an important distinction. Vaseline glass specifically refers to uranium glass with a distinct opaque pale yellow-green colour, reminiscent of petroleum jelly. It is a subset of the broader category of uranium glass, which encompasses any glassware that contains uranium oxide as a colourant and exhibits fluorescent properties under UV light.

So while all vaseline glass contains uranium and will glow green under a blacklight, not all uranium glass has the signature vaseline tint. Uranium glass can range from vibrant yellows and greens to rarer shades like blue, pink, or white depending on the level of oxidation and other additives used by the manufacturer. Properly identifying a piece as true vaseline glass versus general uranium glass is important for collectors and can impact its rarity and value.

The History of Uranium Glass

The use of uranium oxide as a glass colourant began in the late 19th century and peaked in popularity in the early 1900s. It was produced by many American, English, and Central European glassmakers. Some of the most well-known manufacturers include Consolidated Lamp and Glass Company, Fenton Art Glass Company, Regal, and Vaseline Glass Inhalers Company.

Popular Patterns and Manufacturers

Some of the most iconic and valuable uranium glass patterns to look for include:

  • Grape and Strawberry patterns by Fenton Art Glass
  • Coin Spot by Consolidated Lamp and Glass Company
  • Custard glass by Regal
  • Vaseline glass by Vaseline Glass Inhalers Company

Caring for Your Collection

While generally safe, it’s wise to take some precautions when collecting uranium glass:

  • Avoid using for food or drink, even if the piece is described as “table setting” glass.
  • Wash hands after handling, especially before eating.
  • Display safely out of reach of young children as a precaution.
  • Protect from sunlight and heat which can cause colour fading and damage over time.

With some knowledge and care, building a uranium glass collection can be a rewarding experience. Happy and safe hunting!

everything you need to know about uranium glass
Photo credit: Till Westermayer

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