The government confiscated all supplies of uranium during WWII and halted all production of Vaseline Glass from approximately until the ban was lifted in Nov. Pertinent Regulations 10 CFR I guess this will also be a subject for long debate. Uranium was discovered by the German chemist Martin Heinrich Klaprothwho reported his findings in The presumed explanation is that less and less leachable uranium becomes available. However, like "vaseline", the terms "custard" and "jad e ite" are often applied on the basis of superficial appearance rather than uranium content.
The sun is definitely over and under the yardarm for this 19th century uranium glass skull!
Archived from the original on Vaseline and Uranium Glass ca. I guess this will also be a subject for long debate.