Not that I have smelled it, but is it Basala by Shisheido?
No, not Basala (I don't know what genre that one fits in, actually).
I can assure you that all of you are aware of this frag, but it hardly ever gets discussed. I think the fact that no one has guessed it yet is proof of this.
Arpège PH, perhaps?
Not Arpege either.
Here's another hint: this fragrance is very strong, yet it's more of an old school scent than a powerhouse. It fits within the new format of this group, yet it has never been discussed in this group before.
Ahem, ahem!... It's a real jewel of a scent... Ahem!
Emporio Armani Diamonds?
Could it be Hermes Equipage?
Neither of those.
Here's a summary of the clues so far:
1. It's for men
2. Haters call it an old lady fragrance
3. It's a chypre
4. Released after 1990
5. It's a well known scent, but isn't discussed often on BN
6. Still in production
7. You all have heard of it
8. It's a real JEWEL of a frag...
Another clue: it's made by a company that also makes a fragrance that you already guessed.
Your beloved Onyx ?!
The biggest JEWEL of 1990s in my opinion is Havana. But it does not fit with other clues.