Reverse gold conversion reaction

The technology that kicked off the Golden Age of the Dwarf, nearly 450 years ago. In their obsession with gold, many in the dwarven kingdoms had turned to alchemy, seeking a more convenient supply of their favorite yellow metal. It was with a heavy heart that many disappointing dwarven tinkerers revealed that the magiological density of gold was significantly higher than that of lead, and that satisfying the philosopher's equation, while technically possible, would require far more energy than it would take to simply mine it out of the ground.
It was the Dwarf now known colloquially as The Inventor who asked "what happens when you turn gold into lead?" The energy produced by the reverse gold conversion reaction (RG/CR) now powers all dwarven technology, from firearms, to lighting, to The Deep Lines, to industry. It once powered the war machine of the Golden Expansion, as the dwarves sought to manifest their destiny as the sole rulers of the subterrane, and unite the civilized world with the construction of the Deep Lines.
Now the dwarves cower and cling to what remains of their technology, the last thread that they hang by in these trying times.

Utility

Weapons, Light, Transportation, Industry.

Manufacturing

Trade secrets known only by The Inventor and his exclusive distributor, Big Bob's Enterprises.

Inventor(s)

The Inventor of RG/CR tech is, appropriately, The Inventor.

Access & Availability

Frequently wherever there are dwarves, although the level of disrepair tends to be proportionate to how far from the Drilling Platform (where the foundries are located) the tech is found.

Discovery

"What happens when you turn gold into lead?"