Our regular money: Is needed in change and small bills for emergency when power is out.
Silver junk coins, all silver coins, gold coins: This is for preserving wealth to have wealth after a long emergency is over. In a severe emergency, it may be good to have for certain purposes. Someone said use silver/gold coins to pay for medical services, however, if the emergency is that bad, and we know only 3% of the population has three days of food in their house, that doctor will likely want food instead of money. But, we don't know, so have silver and gold coins as another choice for surviving.
Do not buy silver bars or gold bars. You can't sell them until they are assayed again to make sure the bars haven't been shaved down or otherwise altered. You will be stuck with bars you can't sell.