Hi Dep,
I'm just writing this because a famous gold & silver exchange in Tucson did the magnet test on some of my jewelry I was selling that was hallmarked "14k." I wouldn't think a magnet would help determine anything about sterling but good point.
The figero chain that I returned to the store was still one of their staples and they still have that same chain in the cases. I have never been bold enough to ask to see one and then whip out a magnet to check if it stuck or not, but I would never buy anything "gold" there again.
Thanks for writing,
Cat