What is the meaning of "Emerald in Prosperity, Gold in Wartime" and why?

"Jade in the Prosperous Age and wartime gold" is a folk proverb in China, which means that jade and gold are precious items in peacetime, but they can be exchanged for materials in wartime.

Jade is a precious jade with beautiful color and texture. It can be used as an ornament and a collection at ordinary times. But during the war, jadeite can be changed into other materials, because jadeite is of high value in the war.

On the other hand, gold is a precious metal, which has a high value-preserving function. In peacetime, gold can be circulated as currency, but in wartime, gold can be exchanged for other materials because of its high value in war.

Therefore, the phrase "Emerald in Prosperity, Gold in Wartime" means that jade and gold are precious items in peacetime, but they can be exchanged for materials in wartime.