The Curse of Silver / The Gift of Gold

The Curse of Silver and the Gift of Gold are the common names given to the effects of silver and gold on magicians and the supernatural.
The presence of silver is anathema to all manner of supernatural creatures, especially Werewolves and the undead. Silver also greatly disrupts the ability of a magic user- whether this is a Man who bears The Gift, or an Elf using their innate powers. A fear or strong aversion to objects made from silver is often an early warning sign that a child either has Lycanthropy or bears some other kind of magical illness or ability.
Some organisations such as the Order of Oridain use silver-coated swords and arrowheads which make slaying Werewolves and the restless dead much easier. On occasion, mighty beasts have been known to flee at the sight of a silver blade.
Gold has the opposite effect- it invigorates and empowers magic users and supernatural creatures. As well as for its value and rarity, gold is prized among Gifted individuals and Elven Mage-princes for its ability to amplify their powers. For this reason, the famed helm of Aethelwulf was gilded as was his sword Gefea. Those seeking to combat the undead would do well to avoid gold weapons and armour, however, as the usually slow and shambling revenants and draugrs become faster, stronger and more intelligent in its presence.
When spoken in terms familiar to the Universal Argument theory of magic, gold is known to weaken the fabric of reality and make it more malleable and thus open to meddling by sorcerers and supernatural beings. Silver strengthens the fabric of reality, thereby increasing the universe's ability to 'argue'- making it more difficult to alter.