There is a really old film I watched once as a kid. I shall enumerate the facts I can recall, and may be someone would be able to remember it.
- I saw it at least 20 years ago. But it was not black-and-white.
- I think(but not sure) it was made in Soviet/ex-Soviet country (judging by the general appearance and director's work)
- When I watched it, it was in Russian. But I can't recall if it was translated.
- The plot revolved about some amulet, shaped as a yin-yang symbol and separated in two pieces. When one piece of it was put on, it shortened the chain so that it can not be taken off.
- The main hero got the white piece (apparently by accident) and put it on, and was hunted by some evil guys to get that piece back.
- There was some mentor figure, who explained things to the hero. He said he was once wearing the piece of amulet but got tired and freed himself by melting the chain right on his neck. He had a big burn on his neck.
- In the end, the hero completed the amulet. The hero's little daughter put the amulet on, and it locked itself on her neck.
There is one more scene in my memory, but I am not sure it belongs to that film. Two men are looking into the red lava pit amidst grey plane. One of them cites the famous "When you stare into the abyss, the abyss starts staring into you". Immediately, the giant head made of magma appears from the pit and starts looking at the men.
That's all I can recall. Actually, I was sure it was called "The Che Hour" and made in Russia, until recently I learned that it was a totally different film.