The halcyon was a bird, identified with the kingfisher, that had the ability to soothe the winds and waves when it nested upon the sea during the winter solstice. The bird's legend originated in Greece where sailors threw sweet biscuits into the Mediterranean Sea to draw it and then, in the calmer seas, near their ports.
Halcyon have been extinct in Dreaming since before the Shattering, dying with their legend. The last few to die were used to make Halcyon Halters so that their memory was preserved. Decorated with the bird's feathers, this halter makes an X across the chest of its wearer, crossing right over the heart where the brightest feathers stand out.
The treasure soothes the wearer's pain; wiping the memory of sorrow temporarily from the their mind and heart and allowing them relief for as long as they wear it. As soon as they remove the Halter, though, their emotions return, along with the remembrance of why they mourn. This treasure costs one Glamour to use, though anyone can trigger it, not just the wearer.