Radium

Radium is a radioactive element used in luminous paint on early watch dials and hands, before tritium and later non-radioactive materials replaced it.

Radium-era watches are generally older vintage pieces, and their lume often looks dark, cracked, or burnt. Beyond its effect on value and originality, radium lume is a genuine safety consideration: old radium paint should not be disturbed or removed without proper precautions.

If you handle radium-era pieces, don't open or refinish them yourself, and use a watchmaker experienced with them.