I think there is a discrepancy in this translation, maybe from Russian. The German sounds different...

What does the German say?

It's very possible, because the Russian алмаз and бриллиант both translate as "diamond". There is a difference, but my total lack of knowledge in jewelry and precious stones probably didn't detect it. The best I could do (in 5 minutes of quick Wikipedia research) was "diamond" and "gem"...

Oh, but I see the German only has one stone...

K, I fixed it. Let me know if this still doesn't sound right...

The French, Dutch, two Esperanto versions and two German versions all mean: "The diamond in this ring is polished." I don't know what the Japanese and Turkish versions mean.

If the Russian sentence is trying to say something else, such as "This ring does not have a diamond but a semi-precious stone," then it should probably be delinked from all the others. It would still be a valid sentence, just not one with the same meaning as the others.

Isn't deu:geschliffen = eng:cut ??

@danepo
deu:geschliffen also means polished...

@Objectivesea
As I know "алмаз" means a "raw" diamond and "бриллиант" means a facetted diamond.

So does the Russian means something like:

"This is not a native, rough diamond but a polished, faceted jewel."

If so, would it help to separate the two groups of sentences as I suggested in an earlier comment, and emphasize the full meaning in Russian with additional adjectives to possibly make the distinction more clear?

Doesn't it still mean essentially the same by saying that the jewel is not a raw one, but a polished one?
It's probably the most natural way in Russian to translate the sentence, since there isn't a single word for "any" diamond.

@Objectivesea
Yes, it means.

I would translate it as "Алмаз в этом кольце ограненный". More natural sentence is "Это кольцо с ограненным алмазом", but the literal translation of that is "This is a ring with a faceted diamond".