Tersk is a thin iridescent material of Centauri origin that is affected by body heat and chemistry.[1]

Once reserved only for Centauri women of noble birth and used to make certain very fine and expensive gowns that, because of tersk's unique properties never looked the same on any two women. By the 2270s, Centauri Prime's economy had fallen on bad times and that tradition and been waved in the interests of practicality, allowing tersk to be exported as a luxury item to other worlds and could even be found in the Clothiers of Paris, Earth.

In 2271 Alfred Bester, while living in Paris under an alias bought a gown of tersk for his landlady Louise Bouet as a gift for her night at the opera.