Cinnabar / シンシャ
First Appearance: Vol. 1, Ch. 2
Status: Active
Nickname: None
Race: Gem
Age: Unknown (same age as Diamond)
Hardness: 2
Family: The other Gems
Occupation: Patrol (night)
Teammate: None

Cinnabar (シンシャ, Shinsha) is the only Gem who goes on night patrol. Due to their body producing poison which is harmful for Gems and living things, they are isolated and ashamed of themselves. They hate fighting and hate to be seen.

According to Rutile, Cinnabar has an extraordinary amount of talent and combat ability, but is too much to handle due to their uncontrollable poison that ruins everything it touches. Cinnabar's silver poison gathers faint light at night, which keeps them awake and aware while night patrolling. According to Kongo-sensei, the night patrol is something Cinnabar came up with by themselves.

They spend their time during the day in Hollow Cape waiting for the Moon People to take them, since they think they may at least be of use to them. They are knowledgeable about things other Gems don't know, and was recommended by the Gems for Phosphophyllite's work on the encyclopedia.

After accidentally hearing their secret and wish, Phos promises to help Cinnabar find a job more suited to them than night patrol, "a job only they can do".

From the Character Introduction:

  • They're isolated from others because their body produces a poison.
  • Still all by themselves. Still gloomy.

From the Official Website :

  1. They have a hardness of 2. Because of the unique form in which poison emits from their body inexhaustibly. They are in charge of patrolling at night— though Lunarians do not appear—to be at a safe distance from the other Gems. They are wise and thoughtful.


They have a red color scheme and wear the Winter Uniform. They also wear black oxfords and sometimes black gloves when touching something, but no socks. They have a medium long asymmetrical haircut.


They are gloomy and hate themselves for dirtying things with their poison. According to Kongo-sensei, Cinnabar is far too wise and too kind to be alone. Although they try not to show it, they have some hope that Phos will be able to fulfill their promise. They are depicted as being intelligent and thoughtful, able to provide Phos with the information they needed in the Encyclopedia.

Cinnabar also seems to have a form of social anxiety, as in Chapter 65, they have a hard time talking to Kongo-sensei as well as their fellow gems.


Cinnabar is a talented fighter but their body's poisons causes life around them to die. A long time ago, Kongo-sensei wanted them to accept their condition and simply be content with living, but Cinnabar insisted on contributing and doing a job. They came up with the idea of patrolling the land at night where they would not disturb anyone else. Not wanting to reject Cinnabar's own idea, Kongo-sensei agreed to the plan. He once explained this situation to Phos and apologized for still being unable to find a solution to Cinnabar's condition.

Cinnabar plays a major part in the story as a driving force for Phosphophyllite's actions. They both meet directly for the first time when Cinnabar protects Phos from a surprise attack by the Moon People. During this time, Cinnabar reveals the shame they feel at their body and wishes the Moon People would take them away. Phos promises to find them a fun job that only they can do. While Cinnabar does not usually play a direct role in the events of the story afterwards, they do act as an insightful advisor and consultant for Phos as well as the other Gems.

When Phos was believed to have turned into a slug, Diamond seeks Cinnabar's advice on how to turn them back. Cinnabar did not believe Diamond and says that the slug they carry is just an ordinary slug. They further explain that those types of animals eat rocks and minerals to build their own shells, thus indirectly helping Diamond realize that Phos was in fact incorporated into the slug's shell.

After Phos was brought back from the sea, they washed up on shore close to Cinnabar's cave and the latter took them back to the school.

When Shiro attacked the school and was split into copies, one of them was found along with Bort's shoes by Cinnabar. Phos took them back, as well as told Cinnabar about their suspicions that Kongo-sensei is somehow related to the Moon People. Cinnabar reveals that they were already aware of that, and that everyone else was also aware of that. While the other Gems have chosen to believe in Kongo no matter what, Cinnabar has not quite made up their mind yet.

Later, Phos claims to have found Cinnabar a new job helping them find out the truth about Kongo. Cinnabar berates Phos because they promised a fun job that they would like. Phos admits this job is not fun at all, but would still like Cinnabar to help because it is a job that only they can do. Cinnabar asks what Phos would do if they found out a horrible truth about Kongo, to which Phos cannot answer, causing Cinnabar to doubt the other Gem. Phos praises them for their judgement and says that that is the quality that makes them suitable for the job. They leave but promise to come back again to once more attempt to recruit Cinnabar.


Benitoite, whose room is beside theirs, says they can't relax near them. Generally, the Gems all know that they tend to not bother others, but their own existence itself is harmful so they can't help but avoid them.

Diamond is friendly to Cinnabar as they were born in the same year and also because of their personality; they can see what Cinnabar means between words, much to their annoyance. Diamond says that Cinnabar's comment about Phos is more than what they said in the last century. To Cinnabar, Diamond is kind of weird.

Cinnabar first said they envied Phosphophyllite since the latter is wanted by the Moon People. They want to leave the night duty so when Phos promised they will find Cinnabar a job suited for them, they can't help but feel a little hopeful. Cinnabar saves Phos multiple times, making Phos determined to help them back. They picked up Phos' notepad, but did not give it back to them yet. Though they agreed that Phos is useless and a disappointment, they always remembers Phos promise and has held off on labeling them as a liar. Phos themselves is kind of happy to be depended on, as both actually are weak and not useful for their society.

When asked by Phos whether they trust sensei or not, Cinnabar replies that they are still observing. On the contrary, Kongo-sensei cares for them, telling them that they're worth something just by being alive, though they still can't find the best solution for them.

Gem Info

  • Mineral: Sulfide
  • Chemistry: HgS
  • Color: Red, brownish-red

Cinnabar and cinnabarite, likely deriving from the Greek κινναβαρι (kinnabari), refer to the common bright scarlet to brick-red form of mercury(II) sulfide, that is the most common source ore for refining elemental mercury, and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.

Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, in the New World since the Olmec culture, and in China since as early as the Song dynasty, where it was used in coloring lacquer-ware. Associated modern precautions for use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as ancient Rome.

Source: Wikipedia


"To think they'd be on higher level than me, a gem useless since birth. How impressive..!" - Phosphophyllite, about Cinnabar.
"I don't want to dirty anything more than I already have. I don't want to be seen. It's so shameful.. I don't want to fight." - Cinnabar, in Chapter Two.


  • Cinnabar in Japanese originally written as '辰砂/shinsha' in kanji (roughly means dragon sand), but in the series written as シンシャ/Shinsha in katakana.
  • Kongō-sensei and Cinnabar/Shinsa are the only Gems who use Japanese names instead of English in the original Japanese version.
  • Their poison doesn't have a name except 'poison', but it is most likely mercury.
  • Their hair is red, but it is more purplish in the animation PV.
  • Despite the rest of the Gems getting a necklace in the collaboration with TASAKI, Cinnabar did not. This is due to the fact that Cinnabar in real life is toxic.
  • They're voiced by Mikako Komatsu in the anime adaptation.
  • Cinnabar is the first character to appear and speak in the anime adaptation.
  • Cinnabar is able to repair themselves, as in Chapter Two they break several of their fingers by grabbing Phos. In the next chapter, their fingers are shown as normal.
  • They seem to not care about dying or getting shattered, as they are okay with possibly being shattered beyond repair in Chapter Two