Radium dial
instrument dials painted with radium-based paint
Radium dials are watch, clock and other instrument dials painted with luminous paint containing radium-226 to produce radioluminescence. Radium dials were produced throughout most of the 20th century before being replaced by safer tritium-based luminous material in the 1970s and finally by non-toxic, non-radioactive strontium aluminate–based photoluminescent material from the middle 1990s. The gruesome and often fatal radium jaw injuries suffered by early dial painters in the United States became a cause célèbre for occupational safety and labor law in the opening decades of the 20th century.
History
Radium was discovered by Marie and Pierre Curie in 1898 and was soon combined with paint to make luminescent paint, which was applied to clocks, airplane instruments, and the like, to be able to read them in the dark.
In 1914, Dr. Sabin Arnold von Sochocky and Dr. George S. Willis founded the Radium Luminous Material Corporation. The company made luminescent paint. The company later changed its name to the United States Radium Corporation. The use of radium to provide luminescence for hands and indices on watches soon followed.
Begin with the source’s own compact description: “Radium dial” is instrument dials painted with radium-based paint. The dossier treats that line as a proposition to test through Radium, dial and instrument, not as a finished interpretation.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 20, 2026. The linked authority identifier is Q7281380. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1898 and 1914.
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This entry incorporates text from “Radium dial” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.