Basemetal means so much.
Nickel, brass, plated brass, steel, iron, copper, plated brass, pewter, white metal, Alpaca, German Silver.
I once almost bought a load of "sterling" rings from an Indian guy that didn't pass the magnet test. Then he told me they were 40% silver.
If you can pick it up with a magnet it isn't sterling. Or silver.  No matter what he says.