Silver as the next investment

Still with the topic of investments. My sister recently told me about buying some gold or silver coins online and having it safely deposited or kept in a bank. Well, that seems to be a nice idea since a silver coin is getting in demand in the market nowadays. Who knows, maybe if I will buy some today, I can later on sell it a higher price since it's not depreciating. In case you are wondering, it's not just gold that is doing good in the industry but silver as well. If i Wont be selling the silver coins, then I can just keep it for future use, like a gift for my dad who loves to collect coins.