1850: Aluminum was more expensive than gold, and Napoleon III used aluminum tableware to entertain distinguished guests, while gold tableware was reserved for lesser guests.

After the invention of the electrolytic method, aluminum became a beverage can.
16th century: Silver was Europe's hard currency. After the Potosí silver mine was mined, the price revolution shattered its monetary status.
In five thousand years of monetary history, no material's scarcity has withstood technological progress.
Gold will not be an exception; it just hasn't encountered its own "electrolytic method" yet.
The scarcity of materials is guarded by cost, and costs can be rewritten by technology;
The scarcity of mathematics is guarded by theorems, but theorems are not.