Could you distinguish between them if you weren't told?
In final jewelry no. This is why brands like Tiffany are in panic and pivoting to mechanical-watch-like branding, where only inflated price matters.
With close microscopic examination of inclusions and defects, yes you probably can. There are also spectroscopic differences. In general looking at finished jewelry, no, not really.
In final jewelry no. This is why brands like Tiffany are in panic and pivoting to mechanical-watch-like branding, where only inflated price matters.