Hi,
You have the text below the artifact, as if the game decided you haven't got the necklace from the Asari Consort Sha'ira.
Are you sure you did the quest with the Turian general (Septimus I think, he was in the bar) ? And by doing it I mean solve it with charm or Intimidation, so the Consort will give you her necklace?
To add - you should check with Xeltan before that, or her door will be closed and you won't be able to get the necklace.
Btw, this does nothing in terms of achievements or story-wise consequences. You are presented with some Prothean observations on the Cave-Man dudes of old. That's it.
