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RADIUM WATCH HANDS
Ca 1936-1943
Bestfit assortment
no. 6R3 radium watch hands. Radium mixed with zinc sulfide was used to
make watch hands that glowed in the dark. Most of these hands no longer
glow in the dark, not because the radium has decayed (its half life is 1600
years), but because the radioactivity has caused the zinc sulfide to
deteriorate. |