The Witches Heart glows in the dark either blue or green and is around the size of a quarter or bigger. The heart opens up like a locket that can also be used as a diffuser necklace if you create felt pads to fit inside. The longer its exposed to light, the brighter and longer the glow will last in the dark. It comes on a silver colored chain. The chain is 16-24 inches long with extender. Great for a gift or for yourself.