Art Deco Uranium Glass Posy Bowl with Flower Frog | 1930s Bagley Frosted Green

Age of an Item

Antique: An item that is at least 100 years old.

Vintage: An item that is at least 20 years old but less than 100 years old and is representative of its era.

Retro:  A newer item designed in the style of a past era. It is not from that era but is a modern homage to it.

Condition of an Item

Mint: As new, with no signs of wear.

Excellent Vintage Condition (EVC): Shows minimal signs of wear through use but is not perfect.

Very Good Vintage Condition (VGVC): Shows some signs of age and use but is still in good overall shape.

Good Vintage Condition (GVC): Shows clear signs of wear, use, and age.

Perfectly Imperfect: This is not an official term. We've adopted it for the purposes of The Timeless Edit because we believe damaged items still have value. Our definition of Perfectly Imperfect is if an item has visible damage but remains beautiful as a decorative piece or suitable for use in a different capacity from that for which it was originally designed.

Common Flaws found in Antique and Vintage Items

Crazing: Crazing is the existence of web of fine cracks that only occurs in the glaze layer of Fine Bone China and porcelain. It is a normal occurrence, particularly in older items. 

• Clean Crazing: The cracks are clear, without any staining from food, moisture, or other contaminants. Clean crazing can be used as an intentional decorative design element.

• Stained Crazing: This occurs when food particles, bacteria, or other contaminants get into the cracks over time, causing them to darken and become visually conspicuous. Items with stained crazing are not recommended for use with food but are still great for use as a decorative piece or other practical function.

Flea Bite: A flea bite is a tiny, pin-sized chip or nick in the surface of an item. It is a common form of imperfection in older items, especially glass.

Bottom Wear: This is common in older items, especially glass, and is often an indication of age.  Wear to the base of an item is caused by everyday use over time and includes scratches, scuffs, shallow chips, flakes, and flea bites.

 Chip: chips are considered either shallow or deep. A shallow chip is typically inconspicuous. A deep chip is large enough to be immediately apparent.

Flake: a small and shallow chip which breaks the surface of an item.

Scratch: a mark which compromises the surface of an item, and which feels raised, rough or sharp to the touch. Not to be confused with Straw Marks and marks which can occur during the manufacturing process.

Hairline Crack. This is a narrow and tight break going through glaze and porcelain body and is visible from both sides of the item. It is not always immediately obvious and can be missed on first inspection. Generally, a hairline crack does not affect the integrity of the item.

Water Mark/Stain: patches, ridges, deposits and clouding on glass caused by water left standing in the vessel for a lengthy period. Such stains can’t be removed.

Air Bubbles: Air bubbles in hand-blown glass are a natural result of the traditional glassmaking process, where air becomes trapped in the molten glass during its creation. They are often seen as a sign of authenticity, indicating the item is handmade and unique, rather than a defect. While a small number of bubbles is generally acceptable, a high concentration of bubbles may indicate fragility. There are exceptions though. In some cases, air bubbles are an intentional decorative feature where artists have used specific Molds or techniques to control their appearance. Also, air bubbles are found in Depression Glass due to its mass production method, where the glass was quickly moulded with little concern for perfection. These bubbles are a common characteristic that signifies authentic pieces.

Maker’s Miss: This is an unintentional inclusion or air bubble in the item caused or overlooked by the glass blower or maker in the manufacturing process.

Firing Flaw:  This is original flaw cased during the firing process. Examples include pinholes or blisters in the glaze, grit stuck to the glaze, stains caused by an impurity in the porcelain and shrinkage cracks that have opened during the drying or firing process. This is not considered damage.

Straw marks: These are marks on the external surface of glass that look like fine lines or even scratches. They occur when molten glass is cut with shears, and the resulting mark doesn't fully smooth out before the glass cools and sets. They are not considered damage but are instead a common characteristic of old, handmade, or machine-pressed glass. Unlike a scratch, straw marks feel smooth to the touch. Straw Marks are commonly found in Depression and Carnival Glass.

What is Uranium Glass?

Uranium glass, also known as vaseline glass due to its characteristic yellow-green colour, is a fascinating type of Depression Glass that contains small amounts of uranium oxide. When exposed to ultraviolet (UV) light, uranium glass glows with a distinctive bright green fluorescence—a property that makes it instantly recognisable and highly prized by collectors.

Why Was Uranium Used in Glass?

During the late 19th century through to the 1940s, glass manufacturers added uranium oxide to molten glass primarily for aesthetic reasons. The uranium created beautiful yellow, yellow-green, and green hues that were difficult to achieve with other colourants. The amount used was typically between 0.1% to 2% uranium oxide by weight—just enough to produce the desired colour and that magical glow under UV light.

Uranium was readily available and relatively inexpensive during this period, making it a practical choice for mass-produced glassware. Manufacturers had no concerns about its use, as the radioactive properties were not well understood or considered dangerous in such small quantities for decorative purposes.

Production Timeline

Uranium glass was produced most prolifically from the 1880s through to the early 1940s. Production ceased during World War II when uranium was requisitioned for the war effort and later for nuclear energy programmes. While some uranium glass production resumed after the war, it was never as widespread, and stricter regulations eventually limited its use. This makes pre-1940s pieces particularly collectible.

Why Is Uranium Glass More Valuable to Collectors?

Uranium glass commands premium prices in the collectors' market for several compelling reasons:

• The UV Test: The dramatic fluorescent glow under blacklight provides instant authentication and creates a spectacular display that collectors love to showcase
• Limited Production Period: With production largely ending in the 1940s, genuine uranium glass has become increasingly scarce
• Historical Significance: These pieces represent a unique moment in manufacturing history before the full understanding of radioactivity
• Distinctive Appearance: Even in natural light, the yellow-green colour is striking and unmistakable
• Scientific Interest: The combination of art, history, and science appeals to a broad range of collectors
• Rarity: Not all Depression Glass contains uranium, making these pieces special finds

Is Uranium Glass Safe?

This is the most common question collectors ask, and the answer is reassuring: uranium glass is generally considered safe for display and careful handling.

The Facts:

• Uranium glass emits very low levels of radiation—typically only slightly above natural background radiation
• The uranium is sealed within the glass matrix and cannot leach out under normal conditions
• The type of radiation emitted (primarily alpha and beta particles) cannot penetrate the glass itself
• Simply displaying uranium glass poses no health risk
• Brief handling of pieces is considered safe

Recommended Precautions:

• Display Only: Most experts recommend using uranium glass for display purposes rather than for food or drink
• Avoid Prolonged Contact: Don't store food or beverages in uranium glass containers for extended periods
• Handle with Care: Wash hands after handling, as you would with any vintage item
• Avoid Damage: Don't grind, cut, or create dust from uranium glass, as inhaling or ingesting particles should be avoided
• Keep Away from Children: As with any collectible glassware, keep out of reach of young children who might put items in their mouths
• Ventilate: If you have a large collection, ensure good ventilation in display areas

Expert Consensus: Museums worldwide display uranium glass without special precautions. The U.S. Nuclear Regulatory Commission and other health organisations have stated that the radiation exposure from uranium glass is negligible and poses no significant health risk when used as intended for display and occasional handling.

Identifying Uranium Glass

The most reliable way to identify uranium glass is with a UV blacklight torch. Genuine uranium glass will fluoresce bright green under UV light, creating an unmistakable glow. This simple test makes authentication easy and adds to the excitement of collecting.

Uranium glass represents a fascinating intersection of art, history, and science. These glowing treasures from the past are not only beautiful and collectible but also serve as tangible reminders of a bygone era in manufacturing. When displayed responsibly, they make stunning conversation pieces that literally light up under the right conditions.