I've scratched my Mums marble effect laminate fireplace back!

You could try Johnson's baby oil.

There is a special oil you can buy for laminate worktops but it is expensive so it might be worth trying the baby oil first.

MiniMoon

My late mother in law used to dampen a soft cloth with liquid Brasso to take superficial scratches out of her car paintwork.
Only other thing I could think that you could try would be WD 40.

Was going to say the same.. Also check Google.

Could you contact the manufacturers for advice?

...at least that's how I read it.

karmalady the OP thinks it isn't marble. I'm assuming it's rather like a kitchen worktop type laminate.

metal polish and very soft cloth, gently round and round. That marble was originally polished, the shine can be restored

Some good ideas here thanks everyone! I will take more notice next time when it says to test an inconspicuous area first! It's not visible when you look at it straight ahead, but very visible when you look at it from the side. My lovely Mum has damn good eyesight for a 90 year old!

Some water soluble acrylic glue? - the sort children use at school. If it doesn’t work, you can just dissolve it.

Someone has already forwarded the suggestion of clear nail varnish. Yes, it sounds like your best bet. Fingers crossed.

As it's probably a laminate you have obviously taken the surface off.
If the pattern (marble) is still there I'd probably try furniture Polish first to see if by shining it it restore the rubbed-away patch a bit.

Unfortunately I don't think it will actually go away.

A spray acrylic may help. That would be a clearer finish?

My late mother in law used to dampen a soft cloth with liquid Brasso to take superficial scratches out of her car paintwork.
Only other thing I could think that you could try would be WD 40.

The thinnest skim of clear nail varnish/polish it’s worth a try.

Would rubbing on oil help? This is not expert advice, just what I would try, as it would probably wipe off if it doesn't work. Olive oil, or sunflower - I din't suppose it matters.