1937-S Lincoln Cent Question?

I understand that over time, coins can wear down and lose weight, but this one appears to have some gunk on it already... And it's still weighing in half a gram light?

I'm strictly a beginner at this, but I've looked at at least 100k pennies since I started this side hobby. I've never come across a penny this old that tips the scales like As if it were a penny made half a century later.

Thanks for your feedback. I'm Eyeballs deep in pennies and I'm all over the place with the info I'm trying to scroll through in my brain with every Lincoln I flip over and look at

-Cel

Thank you samcoin

to CCF Beavrhauzn.
It is always best to post a full coin photo of the obverse, and a full coin photo of the reverse, as well as one or two close ups if needed. Going by these pics, it looks like an environmental damaged coin, like a metal detector find.
John1