Well I'd say it's more common for gold than silver. But even with silver it's an asset, a store of value. In Columbia you can sell it for currency. Or for a ticket north. You could also get robbed. It's easier to store wealth in metals than goods because you need high volumes of goods and most fluctuate in value.
Anyway, I think a lot of immigrants from developing countries tend to keep gold under the mattress so to speak, just in case. Especially after coming from developing countries or places that have had economic collapses.
My philosophy is have a little bit of gold in a safe and hope I never need it.