How old is it? Tritium has a half life of only 12.3 years, so if it's more than 60 years or so old, there's basically none left (around 3%), certainly not enoug

How old is it? Tritium has a half life of only 12.3 years, so if it's more than 60 years or so old, there's basically none left (around 3%), certainly not enough to make it glow. Radium is much more likely if it's still glowing.