This exquisite amulet is crafted from a unicorn horn, its surface gleaming with a gentle, ethereal glow. The has 3 charges. As a bonus action, you can expend one charge to gain resistance to necrotic damage for 1 minute.
The amulet also possesses a unique feature: by carefully inserting a gem worth at least 300 gold pieces into a small compartment on the amulet, you can alter its protective properties. The gem is consumed in the process. When a gem is inserted, you can choose one damage type from the following: acid, cold, fire, lightning, thunder, poison, psychic, radiant, force, or necrotic. Upon expending a charge, the amulet grants you resistance to the chosen damage type for 1 hour.
The Amulet regains expended charges daily at dawn.