From memory there was a basic Q+A about yourself, then you had to try and select the best items after being told about a customer (from a list they provided, e.g they would say 'its my wife's birthday' and you would ask questions and choose from some jewellery), and then you had to try and sell a random item (i.e. a pen)
We have never asked a potential employee to bring in any jewellery or other personal items for training. The main training is till training and then product knowledge which is purely information. Practical training which is given later would be changing a battery in store and taking out links from a watch.