In The Secret World, there are six currencies as far as I can tell.
- Black Mark of Venice
- White Mark of Venice
- Sequin of Solomon Island
- Sequin of the Valley of the Sun Gods
- Sequin of Transylvania
- Black Button
The sequins are given as a quest reward in each of the relevant areas, so completing quests on Solomon Island will reward you with Sequins of Solomon Island.
Where do I get the Black/White Mark of Venice and Black Buttons from?