What happens to a tile location with a gold coin on it when you occupy the space and acquire the gold coin then use that coin to invest? Does the space no longer contain the coin icon? If you leave the grid that contains the coin yet you have already invested the gold coin does the investment disappear that was represented by the gold coin?

You can not invest coins from the map or any other coin "printed", be it on the map, tech card or great person.

See page 13 under "Investing Coins".

thanks, I overlooked that portion. Could you please help to understand correctly from where do I get the coins that I use to purchase/exchange for the coin markers? Obviously, certian tech cards allow me to collect coins for completing certian actions but what if I reach my limit of coins and then use one to exchange/purchase for a cion marker; am I allowed to complete the action on the tech card again to replace the coin I used to purchase a coin marker?

From our understanding, yes to replace. You succeed in the requirements to place the token, then you spend the token, you can now go through the requirements again.

We had an Arab culture builder and a trade heavy India setup some nice long term investment turns doing that.

kcjones2000 said:

The coins used for investing are only coin tokens.

For example, Code of Laws will grant a coin per turn that at the player wins at least one battle.
Also, some cultural events will cause a coin token to be given to a player to put on their character sheet.

If it doesn't grant a coin token, it can't be invested.

For example, coin on a map tile, coin on a great person token, technologies such as Civil Service.