Vaseline Glass Inkwell

This Vaseline glass inkwell is characterized by its translucent, yellow-green “citron” color.

Characteristics

• The Color: The glass has a distinctive yellowish-green hue that resembles the color of petroleum jelly (Vaseline) as it was manufactured in the 19th century.
• Form: This inkwell was molded or pressed into a faceted geometric pattern to maximize the play of light through the translucent material.
• Fittings: Brass and a hinged lid.

Why It Fluoresces

The most famous attribute of Vaseline glass is its ability to glow a vivid neon green when placed under a UV (black) light.

• The Uranium Connection: This fluorescence is caused by the addition of uranium dioxide to the glass melt during production. Typically, Vaseline glass contains between 0.1% and 2% uranium by weight.
• The Science: When UV light hits the uranium atoms, it excites the electrons, causing them to jump to a higher energy state. As they return to their original state, they emit energy in the form of visible green light.
• Safety: While the glass is technically radioactive, the level is extremely low and considered safe for display in a home collection, as the radiation does not penetrate far beyond the surface of the glass.

Age

• Estimated Date: Circa 1880–1920. While uranium glass has been made since the 1830s, the “Vaseline” aesthetic peaked in popularity during the Victorian and Arts and Crafts movements.