Handmade silver spang necklace

A handmade silver (925) spang necklace with turquoise glass as center piece.

I bought this for 4.50 euro tops (I think it was actually lower) at a thrift store that's usually sharp. I'm not sure what threw them off - the (imo, charming) imperfections like the turquoise glass being slightly off-center or the fact the mark is unusally placed (third pic, half past nine, middle row) and perhaps harder to spot due to the tarnish - but I walked out happily that day.