This amulet is fashioned from a shard of resilient material originating from an otherworldly realm. While you are wearing it, you gain the following benefits.
Spellcasting Focus
You can use the amulet as a Spellcasting Focus for your Warlock spells.
Unknown Spell
As a Magic action, you can try to cast a cantrip that you don't know. The cantrip must be on the Warlock spell list and have a casting time of an action, and you make a DC 10 Intelligence (Arcana) check. On a successful check, you cast the spell. On a failed check, the spell fails, and the action used to cast it is wasted. In either case, you can't use this property again until you finish a Long Rest.