Gold is not an "investment" in that it does not increase in value and the assets you put into it decrease a little for transaction costs. That said, in bad times when the dollar is set to crumble it can be
the sensible method of storing value. Absolutely gold does not increase in value. Relatively it changes inversely with the value of the money. Whereas stocks sink relentlessly or gyrate unpredictably and the value disappears out of the currency so that maintaining one's estate becomes extremely difficult with those media, gold holds its value. If you are a little more pessimistic then physical silver is advisable. You can trade it in smaller units of value.
In the poorer parts of the world, Asia in particular, gold is the only store of value trusted by the populace and every family strives to own some gold as a hedge against severe inflation and hard times.