Horology glossaryDefined term / tritium
Tritium
A radioactive lume material used industry-wide from the 1960s until the mid-1990s, when it was phased out in favor of non-radioactive Super-LumiNova.
Authentication note
Why this detail matters.
Tritium lume ages to a warm cream or amber color, and dials from the tritium era are typically marked "T Swiss T" or similar. A watch dated to the tritium period with lume that glows unusually bright, or that lacks the expected aging color and dial marking, may have a replaced dial or hands.