Kesiera

A kesiera is a jeweled pendant on a chain worn in the hair with the pendant on the forehead. It is commonly worn by Cairhienin women of high rank.

References

NS,Ch12 - After being raised to the shawl, Moiraine is allowed to wear her kesiera for the first time in six years.
NS,Ch17 - Moiraine wears her kesiera as she travels through Kandor.
TEotW,Ch53 - The first use of the One Power Moiraine learned when she was a girl in the Royal Palace of Cairhien was to use her kesiera to focus her ability to eavesdrop.
TSR,Ch36 - Moiraine, Egwene and the Wise Ones eavesdrop on Rand and Rhuarc using her kesiera.
ACoS,Ch19 - Daigian wears a kesiera, a moonstone on a thin silver chain.
ACoS,Ch35 - Caraline Damodred wears a kesiera, a clear green stone on a golden chain.
KoD,Ch21 - Caraline Damodred wears a kesiera, this time a small ruby on a golden chain.
TGS,Ch42 - When Rand returns to the Stone of Tear, Caraline Damodred's kesiera is a white opal on a golden chain.