It'll be one of the ones I've listed above, a lesser one or a bog standard +1 or +2 Halberd. I've done Jaheiras quest a few times now but possibly never payed much attention to the weapon or its name at the time for whatever reason. The halberd you mention is not called "Revians halberd" as there is no such halberd in BG2, subsequently this is the reason I could not place it. Thanks anyway.
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It's bleedin dark down here, slippery too.

Man, that's a pisser.