Gold

From Artemis Fowl

Gold is one thing the Fowls want. Their family motto "Aurum Est Potestas" which means "Gold is Power". Artemis use to value gold more than anything before he became soft. He even asked for one ton of 24 carat gold as Holly's hostage fund and one metric ton of gold as payment for his C Cube when he intended to sell it to Jon Spiro in the Eternity Code. Though, not directly stated, when Artemis asked for his consultant's fee when he agree to help Holly in defeating Opal Koboi, it can be assumed that the fee he is asking for is gold. He has said many times before that his father used to tell him the value of gold. He has often said that gold holds its value and that is why he likes it.

Fairies are similarly obsessed with gold. This is, supposedly, the reason that most dwarves spend their lives mining for gold. It is also the fairies' primary currency.