He didn't give me a sapphire to take to Alduk

'Yes You say 'Yes' An angry dwarven merchant says 'Great, take this sapphire, and run it to Alduk at the Inn of the Eternal Star.' An angry dwarven merchant says 'Give it to him, and he'll tell you all about it.' An angry dwarven merchant says 'I've got a feeling I'm getting screwed by these folks, and I want to know exactly what this is worth.' I was invisible and being chased by Tarus.