Morganite

Morganite (モルガナイト, Moruganaito) is a former Homeworld Gem living on Earth under the guise of being a Human. She was once the sort of caretaker of Quartz, however while she technically doesn't look after Quartz anymore, they still stick close by. Quartz usually doesn't like to admit this, however, as she is embarrassed by Morganite.