National Collectors Mint is a coin and coin-like-object mass-marketing company. They try very hard to do everything within the letter of the law, even if what they do is borderline fraud and deception. Most famously, they made and sold
"coins" claiming to be made from silver salvaged from the ruins of the World Trade Centre. And they were, technically: they are made of pure copper, with a thin layer of 9/11 silver plated on to it. But they are not legally "coins", and they are not made of solid silver.
While I am not familiar with this specific NCM "product", it would not surprise me in the slightest if it were actually "one pound" of pure copper, plated with .999 silver.
It should have originally been issued with a certificate of authenticity that stated its actual specifications. If yours didn't come with one, then it was probably removed by a prior owner in the hopes of propagating the deception.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis