Cluster Gems

"The Cluster" is a forced fusion of former Crystal Gems. It first appeared in "Keeping it Together". It was made by currently unknown means.

Appearance
creepy as hell

"Marble Madness"
The Cluster makes a semi-hidden cameo when Peridot is accessing the Facet Five Kindergarten control room.

"Jail Break"
When Peridot and Jasper are at Sapphire's prison cell, Peridot says to Jasper, "We can't leave yet! The whole point of coming here was to check on the Cluster!".

"Keeping it Together"
The appearance of the Cluster was so horrifying to Garnet that she became unstable to the point where she almost defused. Ruby believes the Cluster was created as punishment by Homeworld for the Rebellion. It was eventually 'poofed' by Garnet and currently resides within one of her bubbles in The Burning Room with the other fusion experiments.

Trivia

 * The Clusters are the first forced fusion in the series.
 * The Cluster is the first fusion to never speak in the series (not counting the screams emitted by it); the second being Rainbow Quartz.
 * Coincidentally or not, if one excludes the Cluster's thumb, it has a glove covering every finger but the middle, while Garnet has a glove covering only her middle finger.
 * The blue "leg" off to the left appears to have the same boots as Amethyst and Ruby.
 * The silhouettes of the Cluster members have traits similar to other Gems on the show, most obviously Pearl's "Pilot" hairstyle.
 * It should be noted that when the Gem fusion's body silhouette appears, each "body" seems to have a similar body type, and hair style, implying that the attempted forced fusion may have been somewhat successful, before they reformed into a limb-comprised hand.
 * When the Cluster's bubbled gem was sent back to the The Burning Room, its gem reshaped itself to appear like the Centipeetle Mother's gem.
 * This was later confirmed to be an animation error by Matt Burnett on Twitter.
 * Each of The Cluster's eyes has one plica semilunaris on either side of itself.

Cultural References

 * The Cluster bears many similarities to Frankenstein's monster from the Mary Shelley novel of the same name.
 * Both are made out of body parts of different deceased individuals, acquired via grave robbing.
 * They are unnatural creations which were created through scientific means.
 * Both are represented as tragic, yet horrifying figures
 * Maybe the containers are a Xenomorph ref.

Gemology

 * A Cluster of gemstones is a result of gems that fuse together due to extensive pressure from being underground. In most cases clusters are usually fusions of the same gemstone, however, in very rare cases, it is possible for clusters to form from different gemstones.

Gemstone(s)
pt-br:Cluster