Council of Thieves
Dwarves in Cheliax:
Cheliax has a tendency to leave noble houses abandoned, their owners dead or disappeared in the night… And the relics and goods salvaged therein do a brisk business.
Dwarven adventurers are quite often drawn to the city to spelunk in these in “urban ruins” for abandoned goods.
Other Dwarves are drawn to the city as emissaries. Whether it is to seek methods of fighting or controlling the fiends they unearthed in their mines (as the rumors say) is still debatable.
Dwarves are shown in great detail on the PFSRD. Feel free to customize as you wish following the traditional rules for swapping racial features (remember you cannot replace a single feature, such as greed, more than once)
I will not bar you from choosing to play a Dwarven Mage. As a general rule however, Dwarves are not overly fond of magic. And if you do happen to play a Mage type Dwarf you are very un-Dwarf like. In this case, you are also likely to be un-Dwarf like in other areas of your personality as well. Because of this, you will have been ostracized from your Clan so this will need to be worked into your background and the way you play your character.