Varks are milimetrical-thick sheets of gold/silver. Varks are used to make silver/gold-foiled sweets. Varks, thus, become high-tier ingredients for food.
Pound one silver/gold nugget, get 100 gold/silver varks. One vark is enough to foil one sweet. The foil is so thin that the metal consumption is too few to produce any noticeable health effect (several micrograms per kilogram of sweets).
https://en.wikipedia.org/wiki/Vark