Investment question? Gold and losing gold

By eagletsi111, in Sid Meier's Civilization: The Board Game

So I my city has gold in it's outskirts, I move my gold up and take a gold coin, correct. next turn I invest the coin. and move my gold down one.

The following turn, the city gets destroyed, and I lose the gold, which I no longer have because I have invested it? What happens?

Nothing since I invested the gold already?

Or do I lose another gold, but cannot go negative?

Also, what if my scout is on a gold and I use that to invest?

Thanks,

You cannot invest printed coins. You do not collect a coin token when you have a printed coin on a territory you own (either through a city or a scout), on a building, on a great person, on a tech card, or on a government card. The printed coin only counts toward your economic victory track.

So where do you get the coins from?

By completing tasks on the technology cards. For example, if you have Code of Laws, you gain a coin token for winning a battle once per turn. When you win the battle you put the coin token on that tech card and move your economic tracker up one position. That coin can then be spent in the start of turn phase on your investment cards.

Ok.

By completing tasks on the technology cards. For example, if you have Code of Laws, you gain a coin token for winning a battle once per turn. When you win the battle you put the coin token on that tech card and move your economic tracker up one position. That coin can then be spent in the start of turn phase on your investment cards.

Got it! So if it printed on the card, or anything else. You don't get a coin, but you move your coin dial up one.

Since you mentioned you don't get coins from technology cards, I was confused.

Thanks,