Emma Grace Frost is a character appearing in American comic books published by Marvel Comics. Created by writer Chris Claremont and artist/co-writer John Byrne, the character first appeared in The Uncanny X-Men #129 (January 1980). She belongs to a subspecies of humans called mutants who are born with superhuman abilities. Her mutation grants her high-level telepathic abilities and the power to turn into organic diamond. Emma Frost has evolved from a supervillain and foe of the X-Men to becoming a superhero and one of the team's most central members and leaders.
https://en.wikipedia.org/wiki/Emma_Frost