Fake #Gold is more common than you think.
Scammers buy real bars with legit serial numbers, hollow them out, fill them with tungsten (similar density), and reseal them to buyers. 
Discussion
Stop spreading lies and educate yourself chump. The stuff inside is actually nutrient paste in case SHTF and the internet goes dark. While #Bitcoin owners will have nothing #gold holders will rule the new world. Most of my bars contain this stuff and I couldn't sleep better.
Just checked my Bitcoin. 100% legitimate.
This story from a few years back comes to mind.
https://decrypt.co/34033/chinese-firm-dumps-83-tonnes-of-fake-gold-on-the-market