pull a piece of the pile fiber and burn it, silk smells like burnt hair, art. silk smells like burnt paper. Walk on it barefoot, if cold art. silk, warm real silk.
Price seems a bit steep (unless you really love it) as there is some damage to the fringe and chinese pictorial rugs are not very popular. Art. silk doesn't wash well and not worth much. I have a similar rug that's chinese real silk pile on cotton, paid $100 (2x4'), feels great to walk on it barefooted (super soft and warm).