Feels stainless and my magnet sticks to it! 
I didnt think a magnet would attract to SS 
...
-beerjet-
Stainless steel is ferrous to a point, so a magnet will
lightly stick to it. Aluminum and bronze will not attract a magnet at all. I did see an aluminum impellor look a similar color before but it had some damage on the egdes and was very worn. Typically a used ss impellor will bring $350 - $450 on eBay and sellers generally price them around $500 at swap meets, that I've seen.