and he said : `` yea '' ; but ufedhin said : `` know then that great store of thy best and purest gold remaineth still , for we have husbanded it , having a boon to ask of thee , and it is this : we would make thee a carcanet and to its making lay all the skill and cunning that we have , and we desire that this should be the most marvellous ornament that the earth has seen , and the greatest of the works of elves and dwarves .