Steven Universe Wiki

Spoilers will be present! Please browse at your own risk.


Steven Universe Wiki
This article is about The Cluster. You may be looking for Cluster Gems or the soundtrack.

Want to stay... But... Can't stop! Going to form! Can't stop! Going to form! Help! Help! Help! Help...

—"Gem Drill"

The Cluster is a massive Cluster Gem buried inside of the Earth's core that was first mentioned in "Jail Break" and first seen in "Gem Drill". It is composed of millions of Gem shards and, in its emerged form, would be larger than the Earth. It assisted Steven in bubbling itself in "Gem Drill" and remained dormant in the Earth's mantle until it was disrupted by the ships of Yellow Diamond and Blue Diamond in "Reunited", after which it partially emerged to help the Crystal Gems. As of "Homeworld Bound", Yellow Diamond vows to restore as many shattered Gems inside of the Cluster as she can.


At some point during the Rebellion, Homeworld Gems no longer saw Earth as a viable colony, likely due to Pink Diamond being allegedly "shattered" by Rose Quartz. Instead of exploiting the planet for its resources like originally intended, Homeworld Gems planned on planting a geo-weapon inside Earth itself with the intent of destroying the planet and any remnants of the Crystal Gems. It is heavily implied later on in the series that Yellow Diamond commanded the Cluster project in order to erase Earth from Homeworld's history, not only erasing the embarrassment of a failed colony, but erasing the overwhelming grief the Diamonds felt for Pink Diamond's alleged death.

These early experiments only combine two or three shards. The Cluster will be a billion times bigger. An inseparable fusion capable of destroying worlds, starting with this one.

—Peridot, "Gem Drill"

The shards of fallen Gems from the ongoing war were collected by Homeworld Gems and experimented upon, forcibly fusing the shards together into Cluster Gems. Once enough experimentation was completed, Homeworld Gems fused together millions of Gem shards. This massive assortment of Gems was then planted into the Earth's mantle at the Beta Kindergarten. When this beast, known as the Cluster, takes on its physical form, it will be much bigger than the Earth itself, completely ripping the planet apart inside-out. As implied by Yellow Diamond and Peridot, Homeworld can then use the Cluster as a weapon to destroy other worlds.


As the Cluster is an aggregation of many gem shards, its personality can be likened to a hive mind. They seem to retain some consciousnesses as a collective, however, as Steven's actions in "Gem Drill" make it bubble itself. This is further shown in "Reunited", where the Cluster behaves as a single entity and fights Yellow Diamond's Ship on its own, recognizing Steven and giving him a thumbs up. It apparently has trouble with maintaining a cohesive form, and constantly worries about losing its form, as evidenced by its statement, "Want form.".


"Jail Break"

The whole point of coming here was to check on the Cluster!

—Peridot, "Jail Break"

The Cluster was first mentioned by Peridot in "Jail Break". Arriving on Earth and checking on it was the primary objective of her mission, with her superior Jasper as her escort and their recent prisoner Lapis Lazuli as her informant.

"Catch and Release"

Look, I know you're scared, but I'm not going to hurt you. And whatever's going on, whatever the Cluster is, I wanna help.

—Steven, "Catch and Release"

Details were later mentioned in "Catch and Release" when Peridot was cornered and finally captured by the Crystal Gems. When Steven released her, she reveals that the "emergence" of the Cluster would be a catastrophic event that would destroy everything on Earth.

"When It Rains"

Open the door, Peridot! If this Cluster is putting us in danger, you need to tell us what it is so we can stop it.

Garnet, "When It Rains"

Peridot explains that after Homeworld no longer saw Earth as a viable colony to mass-incubate Gems, they started doing experiments with the Gem shards, fusing them together to create an artificial fusion as a type of "Gem geo-weapon". She reveals in the Prime Kindergarten Control Room that the forced Gem fusions they were fighting were prototypes for the Cluster, a giant forced Gem fusion at the core of Earth composed of millions of Gem shards. She mentioned that it would be much bigger than Earth if it emerges and takes its physical form, and will destroy the planet once it does so.

"Back to the Barn"

This is the Cluster. A massive, artificial fusion composed of millions of Gem shards. It has laid dormant for thousands of years within this planet's crust. When this Gem activates and takes its form, the result will be catastrophic.

—Peridot, "Back to the Barn"

Peridot mentions the Cluster to the Crystal Gems, revealing the details of what the Cluster actually is. The Crystal Gems then decided to build a drill and try to reach the Cluster before it gets to the end of its incubation period.

"It Could've Been Great"

Gotta find the right file... aha! Cluster, Cluster, where are you, Cluster? Aha! There's the insertion point. Looks like the Beta Kindergarten in Facet Nine. It's the smaller of the two, not nearly as impressive as yours, Amethyst.

—Peridot, "It Could've Been Great"

Peridot reveals the Cluster's location through the Diamonds' computer in the Moon Base. As shown, it is located beneath the Beta Kindergarten and was embedded deep in the mantle approximately 2,500 units down relative to the Barn.

"Message Received"

But the Diamonds are bad! They don't care about the Earth! They wanted to hollow it out, and now they wanna blow it up with the Cluster!

—Steven, "Message Received"

After embezzling the Diamond Communicator, Peridot argues with Yellow Diamond to terminate the Cluster so that they would not sacrifice the organic life for such a Gem geo-weapon. Yellow Diamond replies, "I want my Cluster, and I want that planet to die. Just make that happen." She also orders Peridot to let the Cluster grow undisturbed.

"Super Watermelon Island"

The ground shook. This could be the start of the emergence of the Cluster. Stage 1: Slight tremors every quarter-hour. Stage 2: Full-scale earthquakes. Stage 3: the Earth is destroyed! We're running out of time. We need to drill right now!

—Peridot, "Super Watermelon Island"

The Cluster tries to emerge in this episode and causes some tremors. Peridot recognizes these tremors and says that the Cluster is causing them, but the other Gems believe that Malachite is causing them. After they defeat Malachite and force her to unfuse, the Cluster causes an earthquake on Mask Island, which results in Jasper falling into a fissure.

"Gem Drill"

Ugh! Am I the only one who understands the meaning of teamwork?! Okay, Steven, are you ready to drill down into the planet to depths never before reached by your species to stop the Cluster before it forms and save your world?!

—Peridot, "Gem Drill"

Earthquakes begin rocking Beach City, indicating that the Cluster is only hours away from taking form. Steven and Peridot drill deep into the Earth where the Cluster is located but are unable to pierce the surface of it. As Peridot tries to destroy it, Steven sees faces and hears the voices of the Gem shards comprising the Cluster, and starts to talk to it as he falls unconscious. He convinces it not to form and, instead, to bond with itself. The Cluster begins to take form uncontrollably, however, so Steven attempts to bubble all the Gem shards. He eventually wakes up and notices the Gem shards inside the Cluster are bubbling each other. Steven finishes it off and merges all the small bubbles into one immense bubble, completely encasing the Cluster and preventing it from destroying the Earth.

"Steven Floats"

When Steven goes to the Big Donut, Sadie says that Steven missed all of the earthquakes, referencing those that were caused by the Cluster.

"Steven's Dream"

The Cluster is mentioned briefly by Blue Diamond to Greg, who also mentions that Earth does not have much time left before it is destroyed by the Cluster, not aware of its bubbling.

"That Will Be All"

The Cluster is mentioned briefly by Yellow Diamond, who asks Sapphire if it has already emerged, to which the latter replies it has not.

"Raising the Barn"

Peridot mentions how if it wasn't for herself, Steven would have crumbled under the Cluster's destructive force.


Yellow and Blue Diamond arrive on Earth and awaken the Cluster. Its bubble is popped, and it begins to form. However, instead of going on a rampage and destroying Earth, it manages to stabilize and only form a small fragment of itself in the form of an arm, it sides with the Crystal Gems and fights Yellow Diamond's ship. After both Diamond warships are defeated, the Cluster returns to the core of the Earth and presumably bubbles itself again.

"Homeworld Bound"

Yellow Diamond expresses the desire to undo her Gem fusion experiments, mentioning how she'd like to reconstruct the Gems that make up the Cluster.

"I Am My Monster"

The Cluster appears quite suddenly after noticing Steven's transformation into a monster, briefly holding him back from attacking Beach City and giving Steven's friends time to recuperate thanks to Connie's motivational speech. After briefly dispersing, it then comforts Steven along with many of his friends and family, allowing Steven to return to his normal state.


The Cluster is an immensely powerful geo-weapon designed to obliterate whole planets. The simple act of taking form would result in the destruction of the Earth, after which it would be used to devastate other planets. Unlike other fusion experiments, the Cluster has achieved a degree of control over itself. Its gemstone is immensely durable, withstanding penetration from a drill that could effortlessly pierce several strata of the Earth's crust and mantle.

Its nature as an artificial fusion of millions of Gem shards grants it many unique properties. It is the only known Gem to be able to create bubbles before taking form and to remain sentient and able to converse with itself while itself in a bubble.

Unique Abilities

  • Partial Formation: In "Reunited", the Cluster demonstrated that it can form as only a minuscule fraction of what its actual size is supposed to be, in order to avoid destroying the Earth. When it did so, the portion of it that emerged from the planet's crust in the form of a massive arm was roughly the size of a Diamond's ship. This form is not sustainable, as shown when it began to be destabilized after the fight. The Cluster can voluntarily dispel it at any given time.
    • Extrasensory Awareness: The Cluster's arm was able to precisely interact with its surroundings and with Steven without possessing any visible sensory organ.
    • Immense Strength: When it manifested as an arm, the Cluster punched through all layers of metal and rock between its location and the Earth's surface in mere seconds, and before taking form. Later, it was able to block Yellow Diamond's Ship when it tried to ram into it before matching and eventually overpowering it, also crushing Blue Diamond's Ship in the process.

Episode Appearances


  • The plan to hollow out the Earth was foreshadowed by Ronaldo's conspiracy theories in "Keep Beach City Weird".
  • Peridot refers to the Cluster as a "Gem geo-weapon". This is a play on the term "Bioweapon", Bio- referring to organic life while Geo- referring to rocks and minerals. This is appropriate, seeing as how Gems are a race of sentient gemstones and are thus inorganic.
  • In "It Could've Been Great", a map on the Moon Base reveals that the Cluster is currently located somewhere around Death Valley in Southern California/Southern Nevada.
    • In "Back to the Barn", Peridot was convinced that the Cluster lay exactly at the center of the Earth. It is only in "It Could've Been Great" that the correct location of the Cluster was discovered. This could be due to Homeworld being unable to implant it at originally planned due to the rebellion and the records failing to reflect that, or simply a retcon.
  • Unlike Gem mutants, when the Cluster attempts to reform, its appendages are translucent.
    • Also, unlike Gem mutants, it possesses a rudimentary intelligence — likely because of a hive mind formed from the shattered intellect of the millions of shards that compose it.
  • As evidenced in "Steven's Dream" and "That Will Be All", the Diamonds (Blue and Yellow specifically) were unaware of the Cluster's bubbling.
  • The Cluster's gemstone bears a strong resemblance to an Angel Aura Geode, while its physical form shares strong similarities to the muscular system of a human arm.
  • Whenever the hand of the Cluster loses control of its physical form, it makes the same sound that Amethyst did when she "glitched" for a few seconds periodically during the time she was cracked.
  • The Cluster is the only character to have eight voice actors.

Cultural References

  • The Cluster bears a great resemblance to Lavos, the main antagonist of the Chrono Trigger video game. They are both extraterrestrial creatures that will initiate an apocalyptic event if they are released/awakened unless a group of heroes stops them.


Click to view the gallery for
The Cluster.

Click to view the designs for
The Cluster.

ve Fusion Gems
Crystal Gem Fusions

Full-Gem Fusions
FusionTemplateGarnet3.png FusionTemplateOpalMovie.png FusionTemplateSugilite.png FusionTemplateSardonyx.png
FusionTemplateAlexandrite.pngFusionTemplateRainbowQuartz.png Newobsideon.png NavboxCrazyLaceFixed.png

Hybrid Fusions

FusionTemplateStevonnie.png FusionTemplateSmokyQuartz.png Rainbow Quartz 2.0 Gem Nav.png Sunstone Thumbnail fixed.png FusionTemplateObsidianS.png Steg Nav.png

Homeworld Gem Fusions

FusionTemplateMalachite.png Ruby quintuple fusion gem.png FusionTemplateJasperMonster.png
FusionTemplateTopaz.png JadeFusionNavbox.png BluebirdAzuriteNavbox.png

Crystal Gem/Homeworld Gem Fusions


Unaligned Gem Fusions

RhodLink.png FluoriteLink1.png

Forced Fusions

FusionTemplateCluster.png Cluster Navbox.png

ve Characters in Steven Universe
Crystal Gems Human-Gem Hybrids: Steven Universe

Unfused Gems: AmethystBiggs JasperBismuthLapis LazuliLarimarPearlPeridotRubySapphireSnowflake Obsidian
Fusion Gems: AlexandriteCrazy Lace AgateGarnetMega PearlObsidian (Rose Quartz Fusion)OpalRainbow QuartzSardonyxSugilite
Hybrid Fusions: Obsidian (Steven fusion)Rainbow Quartz 2.0Smoky QuartzStegStevonnieSunstone
Inactive Gems: Rose Quartz
Humans: Connie Maheswaran
Pets: LionPumpkinCat Steven

Homeworld Gems Unfused Gems: CombyEmeraldPebblesPeridotsSapphiresSpinel

Fusion Gems: MalachiteTopazZebra Jasper (fusion)Giant RubyRuby (triple fusion)Lemon JadeBluebird Azurite
Inactive Gems: Pink Diamond

Off Colors Unfused Gems: PadparadschaRutile Twins

Fusion Gems: FluoriteRhodonite
Humans: Lars Barriga

Other Gems (Formerly) Corrupted Gems: AlbiteAngel Aura QuartzBig Bird • Biggs Jasper • BixbiteBlue ChalcedonyBlue Lace Agate • Cherry Quartz • ChrysocollaDesert GlassEarth BeetleGrossular DiopsideHeaven Beetle • Jasper • Lace Amethyst • Larimar • Moonstone • Nephrite • Ocean JasperOrange Spodumene • Snowflake Obsidian • Tongue MonsterUnknown Giant Gem MonsterWater BearWatermelon TourmalineWhite TopazZebra Jasper (singular)Minor Corrupted Gems

Other Gems: Minor GemsUnknown Gems (Morganite • Nephrite-XJ Cut-763 • Unknown Quartz Warrior • Blue Diamond's Court • Pink Diamond's EntourageUnknown Crystal Gems67 Elite CitrinesPyritesHessonites, Demantoids, and PyropesKyanites)

Forced Fusions: Cluster Gems (The Cluster)

Comic Gems: Ant Gem MonsterClock Tower GemFrozen FragmentGlass GhostInvisible Manta RayMole Gem MonsterMolluskMonster Lizard GemObeliskOld Book GemPlant MonsterPerils of PweepweeRainbow Cloud MonsterRed Bird Gem MonsterRed Eel MonsterScorching ShardSlime Gem MonsterSlug MonsterSnowbeastTentacle MonsterUnknown Giant BirdVine Monsters

Other Major Characters Humans: Greg UniverseSadie Miller
Recurring Characters Humans: Andy DeMayoBarbara MillerBill DeweyBuck DeweyBuddy BuddwickDante and Martha BarrigaDoug MaheswaranPriyanka MaheswaranHarold SmileyJamieJaneJenny PizzaKevinKiki PizzaKofi PizzaMartyMr. FrymanMystery GirlNanefua PizzaOnionPeedee FrymanQuentin FrowneyRonaldo FrymanShepSour CreamSuitcase SamVidaliaYellowtailZoomans (F-3Jay-TenU-12Wy-Six)

Other: Baby MelonBlue CrabsCactus StevenHolo-PearlMagic MossSteven Jr.Watermelon Stevens

Minor Characters Humans: The Best Diner in the World's WaitressEmpire City Wildlife Rehabilitation Center EmployeeGaryGreg's family (Aunt and Uncle • Aunt DebGrandfatherParentsGreat-aunt Gregargia) • Hospital Employees (Dr. GeroDr. StrombergDr. West) JeffKhajima, Jaime, and BrandishMarty's RoadiesMayoral BodyguardsMike KrolOnion's Friends (Garbanzo • Pinto • Soup • Squash) • Patricia and DanielRickySabinaSteven's BabysitterSunshine JusticeWilliam Buford BuchananWilliam DeweyMinor Human Characters

Animals: Butt LobsterCrystal BasiliskDogMask Island FishOnion's MouseOnion's SnakeParty GuyRaccoonSeagullsSnakeSteven The ThirdSusanMinor Animal Characters
Aliens: Beetle AliensBird Blob AliensUngulate AliensWorm AliensFlower-Like AliensMinor Alien Characters

Fictional Characters Cookie CatDogcopterMearlPizza JennyMinor Fictional Characters

Camp Pining Hearts: PaulettePercyPierre
"Garnet's Universe": FoxmanHopperHoppyRingo
Golf Quest Mini: AceAce's Father
Li'l Butler: Li'l ButlerMr. MoneyMrs. MoneyDaughter Money • Dirtbike Money
Lonely Blade: Evil JanitorLonely BladeLonely Blade's Brother
Rose's Room: Cloud ConnieTiny Floating Whale
The Spirit Morph Saga: ArchimicarusLisaPlinkmanWind Lizard

Antagonists CentipeetlesCrab MonstersCrystal ShrimpDrill ParasitesElectric SkullsFryboRed EyeRobot Shooty ThingSmoke Monster
Alter Egos Billy Bank AssetsChunk TruckConcrete HeatDashing Danny DooberHandsome Hank HackleschmidtHowl JonesLoch Ness BloggsterPurple PumaSea WaspShark-O-ManiaTiger Millionaire
Attack the Light Blue LightGreen LightIndigo LightOrange LightRed LightViolet LightWhite LightYellow Light

Groups: Light ArmyBlue Monsters • Green Monsters • Indigo MonstersOrange MonstersRed Monsters

Save the Light Hessonite • SquaridotHessonite's Citrines
Unleash the Light DemantoidPyrope
The Phantom Fable Fable • Lonely PearlJasper (Eyeball)
Groups The Cool Kids • Crystal Gems • Crystal Temps • "Famethyst" • The Great Diamond Authority • Homeworld Gems • Off Colors • Pebbles • Sadie Killer and the SuspectsSecret Team • Steven and the Stevens • Water ClonesZoomansSpecies
Gem Types Aquamarines • BismuthsDiamonds • GarnetsJades • Lapis Lazulis • Nephrites • Pearls • Pebbles • Peridots • Quartzes • Rubies • Sapphires • Topazes