Read the link i posted.. the guy explained about Aluminum.
The most you can find on Earth is tiny flakes of it in small quantities in very rare locations.
We only learned that recently too.
It has to be created.. with Electricity.
8% of the US's power grid each year goes to making Aluminum.
In Ancient times Aluminum was worth more than Gold or Platinum.
So there is no chance in hell that slab containing 90% aluminum was man made ..unless it's fairly recent.
There has never been any ancient artifact found made of Aluminum.. like a Kings Crown.
Understand metal is the key and maybe carbon dating.
A lot of metals are simply a pot of elements i think.
There is various elements added into the mix to give various properties or features.
Circumstantial evidence suggests a digger left the old worn teeth in the hole he was digging.
I think they fucked up dating it and it was aback hoe / digger tooth.
I bet if they flipped it over it would say CAT stamped on it
..some "teeth" do have that stamp