Using your newly constructed museum, you borrowed the orb from Sachertorte in the name of using it as a decorative art piece to commemorate the museum's opening.

However, procuring real Dinosaurs' fossils for your museum would require an enormous cost of money and effort...

That's why instead, you prepared fake dinosaurs' fossils made from common material for the fake museum.

My friend who works in forensics told me, that the bone she thought she brought back, turned out to be only stone....

Hahaha! I guess you don't know what you're talking about...

Places that don't have enough fossils to exhibit have to supplement it with using imitations. That's a common problem.

So they brought back one piece of fake bones, that doesn't prove that the rest of the fossils are forgery.