It looks like an old screwdriver or chisel to me
An acid test will tell which of the two metals (if it's one or the other) You should also be able to tell by the weight.
Does it weigh three ounces or ten ounces?
Then I would say it's not aluminum. Does a magnet attract to it?
That would be my guess too, at this point.Could be stainless steel also.
I have an idea, but would first like to see a photo(s) of the head as well as the point. Also, what is the diameter? When it was found, was it vertical or horizontal in the ground?
Judging by the photo, and the fact it does not attract a magnet, it looks to be stainless steel.
Breezie