gold can be cursed
If you pray until your god curses your inventory, this will curse your gold.
That is, if you equip your gold pieces in your weapon slot you will be unable to unequip.
I also have the impression that merchants throwing cursed gold deal less damage to
undead. If the PC picks up gold while also carrying gold, the stacks are merged, even if
they have different item status.
It seems gold was supposed not to have an item status? In any case, this behavior is
weird and probably a bug.