📜 Key facts
| Age | Made since the 1830s, and most popular from the 1880s to the 1940s (Vaseline and Depression glass) |
|---|---|
| Origin & sources | Man-made, not a mineral. It was produced widely in Bohemia (Czech Republic), Britain and the USA, and some is still made today. |
| Composition | Glass coloured with a small amount of uranium oxide (often about 2% uranium by weight) |
How it forms
Uranium salts are added to molten glass. The uranyl ions give a yellow-green colour (an oily look gave it the name 'Vaseline glass') and a vivid green glow under UV light.
⚠ Handle With Care Low caution
Why: Man-made glass coloured with a small amount of uranium (often around 2% by weight). It glows bright green under UV light. Its radioactivity is low, and ordinary handling and display are considered low-risk.
Safe handling: Display and handling are fine. Don't grind or drill it, and don't use chipped pieces for food or drink.
Sources: Wikipedia: Uranium glass · US EPA RadTown: radioactive material in rocks & minerals. General safety information only, not medical advice. More on safe handling.
✺ Glows under UV
| Longwave UV (~365 nm) | Bright green |
|---|---|
| Shortwave UV (~254 nm) | Bright green |
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Uranyl ions in the glass give a vivid green glow under UV, which is the classic collector's test. The same uranyl glow appears in hyalite opal and autunite.
Reactions vary by locality and specimen; many specimens of a fluorescent species do not glow. Shortwave UV can burn skin and damage eyes. Wear UV-blocking glasses, and never look into any UV lamp. Sources: Wikipedia: Uranium glass. More UV-reactive stones →