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The Science Behind Uranium Glass: How it Glows in the Dark

Updated: Jun 21, 2023

Uranium glass, also known as Vaseline glass, is a type of glass that glows under ultraviolet light. This unique glass has a fascinating history and is still produced today. Learn about the science behind uranium glass and its uses in this article. (Science Defined)




What is uranium glass?

Uranium glass, also known as Vaseline glass, is a type of glass that contains small amounts of uranium oxide. This gives the glass a yellow or green tint and causes it to glow under ultraviolet light. The amount of uranium in the glass is very small and poses no significant health risk to those who handle it. Uranium glass has been produced since the 19th century and is still popular among collectors today.


Uranium glass was first produced in the 1830s and became popular in the late 19th and early 20th centuries. It was used to make a variety of items, including tableware, vases, and decorative objects. The uranium oxide in the glass gives it a distinctive yellow or green tint, depending on the amount of uranium used. When exposed to ultraviolet light, the glass glows a bright green color, which is why it is also known as Vaseline glass. Despite containing uranium, the amount in the glass is very small and poses no significant health risk to those who handle it. Today, uranium glass is still produced and is popular among collectors for its unique color and history.


uranium glass, vaseline glass, depression glass
uranium glass


How does uranium glass glow in the dark?

Uranium glass, also known as Vaseline glass, has been around since the 19th century and is prized by collectors for its unique glowing properties. The glass contains small amounts of uranium oxide (typically less than 2%), which gives it its distinctive green or yellow color. But it’s not just the color that makes uranium glass special - it’s the way it glows under UV light. This effect is especially striking in dimly lit rooms or under black lights. While uranium glass is safe to handle and use, it is important to note that the uranium content is still radioactive and should not be ingested or inhaled. So, while it’s a fascinating material to collect and admire, it’s important to handle it with care.


Uranium glass glows in the dark due to the presence of uranium oxide, which is a radioactive substance. When the glass is exposed to ultraviolet light, the uranium atoms in the glass absorb the energy from the light and become excited. As the atoms return to their normal state, they release the energy in the form of visible light, causing the glass to glow.


The reason uranium glass glows under UV light is due to the phenomenon of fluorescence. When UV light hits the uranium atoms in the glass, it excites the electrons in the uranium atoms, causing them to jump to a higher energy level. When the electrons return to their original energy level, they release energy in the form of visible light, which is what causes the glass to glow. This effect is similar to how a black light works, which also emits UV light to make certain materials glow. While uranium glass is safe to handle and use, it is important to note that the uranium content is still radioactive and should not be ingested or inhaled.




The history of uranium glass.

Uranium glass has been around since the 19th century, when it was first produced in Bohemia (now the Czech Republic). It became popular in the early 20th century, particularly in the United States, where it was used to make decorative items such as vases, bowls, and tableware. During World War II, production of uranium glass declined due to restrictions on the use of uranium. Today, uranium glass is still produced and collected by enthusiasts around the world.


Uranium glass gets its distinctive green or yellow color from the addition of uranium oxide to the glass mixture. The amount of uranium used is typically very small, and the glass is not considered to be radioactive or dangerous. In fact, the use of uranium in glassmaking was seen as a way to make the glass more durable and resistant to fading over time.

Uranium glass first became popular in the late 19th century, and its popularity continued through the mid-20th century. It was used to make a variety of decorative items, including vases, bowls, and even dinnerware. The distinctive color of uranium glass made it a popular choice for collectors, and it remains a sought-after item today. While the use of uranium in glassmaking has declined in recent years, uranium glass continues to be appreciated for its unique beauty and historical significance.




Safety concerns with uranium glass.

While uranium glass is generally safe to handle and use, there are some precautions that should be taken. The uranium in the glass is in a stable form and is not harmful unless ingested or inhaled in large quantities. However, it is still recommended to wash your hands after handling uranium glass and to avoid using it for food or drink. Additionally, some antique uranium glass may have small cracks or chips that could release small amounts of uranium dust, so it's important to handle it with care and avoid inhaling any dust. Learn more about uranium glass safety here.



Collecting and appreciating uranium glass.

Uranium glass has been a popular collectible for many years due to its unique glowing properties and historical significance. Many antique pieces can be found at flea markets, antique shops, and online auctions. You can even buy it on Amazon! Some collectors even specialize in uranium glass and have extensive collections. It's important to handle and store uranium glass carefully to avoid any damage or exposure to uranium dust. With proper care, uranium glass can be a beautiful and fascinating addition to any collection.



Uranium glass, also known as Vaseline glass, was first produced in the late 19th century and continued to be made until the 1940s. The glass contains small amounts of uranium oxide, which gives it its distinctive green or yellow glow under UV light. Collectors are drawn to the unique beauty of uranium glass, as well as its historical significance as a product of the atomic age.



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