It's a 602-lb. gemstone pendant that only a museum could wear. And the Gemological Institute of America's president Bill Boyajian is personally spearheading the campaign to acquire the magnificent gem sculpture and have it installed at the entrance to GIA's permanent museum. Bahia, a 426-lb. finished rock crystal quartz included with golden fibers of rutile, is mounted in a gold-colored metal frame complete with internal halogen lighting. Found in Bahia, Brazil, and created by gem artists Glenn Lehrer and Lawrence Stoller, Bahia has been displayed at GIA once before as well as at the Carnegie Museum in Pittsburgh and the Natural History Museum in Los Angeles. It hangs in the small alcove of GIA's Tower of Brilliance, located just inside the main entrance to the institute's headquarters in Carlsbad, Calif. The late Dr. Vince Manson, GIA's former director of strategic planning and "dir