An effective way to turn your cobblestone into Nether Quartz and Gold Nuggets through the use of Washing and Haunting.

A slightly more expensive build, but at the point you need large quantities of both it shouldn't be too terrible.

Don't forget to add water in front of the fans, and to light the soul sand on fire! :)

Also, this uses redstone links, make sure the frequencies don't mess up your own links!