Plastic Filled Gold Wire?

Hi All

While working at my bench today I pulled a job envelope marked
"solder at break". Inside the envelope was a gold colored chain,
stamped 14K, that had been broken in two places. The chain appeared
to be made of .8mm wire but felt light compared to it’s apparent
size. I then suspected that this chain may have been made with
hollow wire but also thought that it might be repairable using the
laser.

When viewed through the stereoscope of the laser the broken ends of
the link appeared to be solid wire which could be fused easily with
the laser. However when I fired the laser an interesting thing
happened, a thin layer of the gold colored metal was vaporized to
reveal a plastic core within the “wire”. That explained this chain’s
lack of heft but more to the point, did I happen upon an example of
a fraudulent practice or is this “plastic filled gold” somehow an
exception to the quality stamp standards? Thanks.

David L. Smith, JT