I purchased this bracelet online recently,with the description that the black stones are onyx, made in Mexico, and the silver is marked.

But when I tested the silver with a magnet, the STONES reacted. Apologies for the second photo, which is a bit fuzzy, but I could lift the whole bracelet up when I applied the magnet.

I tried to search for "magnetic black stone" but didn't get much clarity.

Does anyone know what this could be? Or know of another resource I could use to find out?

Thanks!!!!