That leather smell: cow skin, chemicals, or both?

Does the distinctive smell of leather come from the smell of cow skin, the chemicals used to treat the skin and make itinto leather, or a combination of both?

I’m guessing it’s 90 to 100 percent chemicals.

Can I bump this after so long? Still curious…

I would think it is a combination of the leather itself and the tanning chemicals. Think of how rawhide, which is untreated leather, smells (aka dog chews) compared to tanned leather (purse, wallet etc…).