Halite

Halite is the homeroom teacher of Ruby's Class in Jewel Land. She is an expert magician who teaches the Jewelpets how to use their magic successfully. She has the same role in Twinkle though She sometimes scolds Moldavite when he's sleeping in his speech and to his really funny but annoying antics. Her Jewelpet assistants are Luna and Milky. Her name is based on the mineral Halite, commonly known as Rock Salt.

(Source: Wikipedia)