When meeting Spekkio for the first time, he will explain that there are four types of magic: Fire, Water, Light, and Shadow. Crono's party has magic in them, which allows Spekkio to grant them magic. Crono (Light), Marle (Ice), Lucca (Fire), Frog (Water), and Magus (Shadow) can all learn magic, while Robo and Ayla cannot, due to Robo not being a life form and Ayla existing before magic was created.
There are two Techs that Marle can learn that are Ice-based.
There is one tech that Magus can learn that is ice-based