You should remove it when you are in contact with water, swimming, bath, shower! I don't sleep with mine on either anymore as I found after a few months the colour was changing, so just place it under your pillow at night! But with good care it should last for a while, forever is a long time &everything changes so I'd stay it won't stay like that forever especially as its only stainless steel, the colour does change with stainless steel
try google it also
Completely agree with Sophie, no matter what anyone tells you nothing lasts forever and even thou it doesn't rust the colour will change especially as you probably brought it from somewhere like Argos
Stainless doesn`t tarnish you idiots !
No, stainless steel does not tarnish. Wear it always. I never take my cross off, I feel lost without it. Edit. Look at your kitchen sink and fittings. They are all made with stainless steel. Water does not effect it and it will not change colour or tarnish and will last forever.My husband is a truck driver and wears a stainless steel cross and I gave that too him 6 yrs ago and to this day, it still looks like brand new. Look at body jewellery, it is stainless steel. I think the poster above was thinking about sterling silver........................