I think we all need to be very aware of the way names get attached to pieces of jewellery.
Without actually taking loads of hours to track this down, I think the various pieces of emerald jewellery Queen Mary wore for the Durbar - Cambridge and Indian - have had "Durbar" attached to them - at various times and in various places.
That habit does not clarify provenance, and does not help in our research here.
I think the Royal Collection have on occasion, when preparing items for an exhibition, attached a key word from an event, eg, coronation, when a key word, or two, from its provenance would have served better, for ongoing records, research, and discussion.
Edit: I might just add that fine differences in meaning between words in English will not be immediately spotted, of course, by members who do not have English as a first language. [The same would go, of course, if we were dealing in another language or another.] But hang in there! All this "Durbar" stuff can be clarified.