Hello and welcome to the forum. Your scepsis is right. It is not mulberry silk, it is viscose. If you touch the pile it is soft, if you touch the back it is hard - this is because it is fixed with glue. It is not only sold in India - also dealers all over the world take customers with these rugs:
http://rover.ebay.com/ro...&mtid=824&kw=lg
The described item is the same quality as yours and the seller also states it is silk pile on silk warp on the description of this rug.
He is also offering this on:
http://rover.ebay.com/ro...&mtid=824&kw=lg
Which is described as art silk on art silk which is almost correct. The price he is asking there is just about the regular retail price.
I hope you didn' pay too much for it.