The normal color of uranium glass varies from yellow to green depending on the oxidation status and the addition of metal ions. They take on a green color under UV light. The name petroleum jelly is only used with those with a yellow color (similar to the color of petroleum oil at the time). Uranium glass became popular in the mid-19th century with the greatest popularity between 1880-1920. The first major producer was the Austrian Xayer Riedel in Bohemia in 1830. By the 1840s many other European glass manufacturers were also making uranium glassware. Even now there are still a few manufactories that make uranium glass. The concentration of uranium in petroleum jelly glass is around 2%, but in the early 1900s this could rise to 25%.

Presented are two identical long mouth-blown narrow vases. They have a spherical body that tapers into a long narrow vertically stratified cylindrical neck that spreads into a lobed rim at the top. At the bottom we see a smoothly polished pontille. One vase is slightly lighter in color than the other. The vases are not marked.

Condition: both perfect.