It's mined and refined on-site on various moons and planets, then sent to Ferenginar (or wherever) to be minted into currency
Huge robot-driven bulldozers shoveled the gravel onto a conveyor belt, which carried it into an immense box that radiated heat in waves--probably a smelting furnace, Ttan thought. She'd never seen one quite like this before, but she knew the general principle. Inside, the gravel was reduced to its composite minerals, then put back together into ingots of pure latinurn or rhodinium or carbonire or whatever else it had been programmed for. She couldn't see where the ingots came out of this one, though.
"As you may have already guessed," Gul Mavek said, "Davonia is a working moon. We have found traces of latinum on this level. I want you to find the main deposit for us." Moon? Ttan wondered. Where in the Great Plan had they brought her?
Apparently there are deposits on Ferenginar itself.
GOUGE-MINING MAGNATE ESCAPES DEATH
WIFE CHARGED IN MURDER ATTEMPT
In the early morning hours, latinum mining king Squeeb, son of Been, was hauled from the flaming wreckage of his skimmer by two members of his private medical staff.Though suffering from various injuries, Squeeb is expected to make a full recovery.
Raw latinum metal is apparently solid, not liquid. It needs to be smelted and processed to remove the impurities and turn it into its pure liquid form.
Peeking around the side of the vat, Jake looked to where his friend pointed. A gigantic gray box stood in the middle of the cargo bay. A worker using an antigrav lift stood beside it, cranking the box’s top back to reveal a load of raw, unprocessed latinum.
