Strange portal dropped a bunch of gold. How to make it reappear?

Yesterday while exploring the Jungle in a new 1.3 World, I encountered something very interesting. Suddenly a gold-ish swirl appeared directly on top of me, and started to drop goldpieces. It stayed for a very short time, maybe five seconds, and then disappeared after dropping about 10 gold. I was busy evading hornets and slimes, and I died soon thereafter anyway, so i do not recall what triggered it.

Is this random? Can I intentionally trigger this? I did not see it mentioned in the wiki yet.

Solution 1:

From 1.3 PC Changelog

Coin Portals have a chance to spawn after breaking pots.

That was one of them

Solution 2:

I was really interested in the fact that you didn't see that on the wiki so I made a little of research on those Coin Portals and found this:

"On breaking a pot, there is a small chance that a Coin Portal spawns in place of the pot's normal drops. Coin Portals dispense between 5-15 Gold Coins one at a time before disappearing."

Source: Terraria Wiki: Pot Page