Was wondering if mining guild increases gold production from gold mines, or does it just do iron.  I guess that market add50% to gildar which technically increases the output of a gold mine, right?

What are some other ways to increase gold?  (Would like to see an all inclusive list?) maybe a max gold per city list?

**Edit**

Based on the responses below, I put up a more detailed summary:

Income :

Gold mine   5 Gildar
Merchant    1 Gildar
Palace      7 Gildar

Total 13 Gildar

Market +25%
Bazaar +50%
Trade Center +50%
Mint of Gildar +100%
Total % increase: +225% (29.25 Gildar increase)

Total Gildar income: 42.25 (13 + 29.25)

The math seems a little odd but this matches an example city. There is also consumption (for example a school costs -1 Gildar) that I ignored in this case. Researching trade tech will give you a 10% bonus to gold production in all your cities per tech level. Also did not count the city level bonus. Suggest naming cities with gold mines as Money1, Money 2,etc... so you don't miss the city level bonus that comes up.

Note that the Mining guild does not count, it apparently only applies to metal (like the description reads).

You can also get a similar breakdown by bringing up the book view of your town (click on the circle in the bottom center of your screen) and then clicking on the gildar line.

 Thanks for everyone's help below.