A silver-plated spell book locket engraved with a moon, star, and other witchy symbols — half-inch, with an opening compartment. Fill it with a scrap of paper holding a petition, a pinch of herb, or something small for the working to carry.
Witch Tip: Write a single word intention on a slip of paper and seal it inside the locket for a month — it turns the necklace into a working spell, not just a piece of jewelry.