Krystal Jung (Korean name: Jung Soo-Jung; Hangul: ÿ???ÿ?; Hanja: ‚??‡??‘??; born October 24, 1994), better known by her first name Krystal, is an American singer, dancer, model and actress. She was born in San Francisco, and is fluent in both Korean and English. She is a member of South Korean girl group f(x), formed by SM Entertainment in 2009 and is the main vocalist. Her older sister, Jessica, is a member of SM Entertainment’s SNSD.