[Source] Crystalplas was a transparent substance used as a building material during the time of the New Republic. Some galleries made of crystalplas were part of the Museum of Applied Photonics on Obroa-skai in 27 ABY. At that time, the planet was under the authority of the alien Yuuzhan Vong who had captured it during their invasion of the galaxy. Despite the worldshaping they did on much of the planet, the Yuuzhan Vong left the galleries intact, to both learn about their enemies and use the museum as a personal base of operations for Warmaster Tsavong Lah.