Gold is the internal temporal pulling metal. An Allomancer burning gold is able to see who they could have been in the past, had they made different choices. Feruchemists can use gold to store health, and when used as a Hemalurgic spike, gold steals temporal Feruchemy.
Allomantic Use
A gold Misting is known as a Augur. Due to the emotional stress associated with seeing one's alternate past, gold is not a very useful metal. Furthermore, touching the gold shadow while burning gold causes unpleasant side effects.
Feruchemical use
A gold Ferring is known as a Bloodmaker. Gold is used to store health. This is very useful, as tapping a goldmind allows a Feruchemist to survive wounds that he otherwise may not. It is hard to fill a goldmind, due to the fact that it requires the Feruchemist to spend time sickly and weak.
Hemalurgic Use
It is not currently known what gold's Hemalurgic property is. It is theorized that it steals Feruchemical Temporal powers, so Inquisitors can use their gold spikes as goldminds to heal.