Phosphophyllite

The main protagonist and the youngest gem when the story began. They're weak, brittle - not suited for battle - and their clumsiness makes them difficult to maintain any roles, even though they've always wanted to be useful. Phos' initial job was to make a natural history encyclopedia which they progressed very little on. They promised to help Cinnabar find a job suited for them as well.

Phos is a young, overconfident, clumsy, and naive gem, who is the only one capable of getting away with talking back to Kongou. Many gems describe them as lazy and useless due to their fragility and incompetence, although Phos does display a drive to help Sensei and the others, often held back by their low hardness. There is an underlying way of how Phos acts and speaks about themselves that hints at them taking the “useless” and “lazy” comments to heart, and impacting their self-esteem. These facts indicate that Phos may have something of an inferiority complex. They settle with what they can do and constantly state that they will try better next time. Phos displays a change of personality over the course of the series, mainly due to maturing, trauma, and outside influences. This is mainly due to the fact that the gems are not equipped to deal with trauma.

Phosphophyllite wears a standard winter uniform and black shoes without socks, occasionally accompanied by long black gloves. Phos has mint-green features known by the gems and the Admirabilis as the Lunarians' favorite color. Their hair is short, originally just beneath the ears, but cut shorter in later chapters to imitate Antarcticite's hairstyle.