Fusion Gems

"Opal is an amalgam of our mental and physical attributes fused into a single entity."

"Fusion Gems" are the product of two or more Gems who fuse together, creating an entirely separate entity. Fusions are commonly formed in a state of emergencies.

Description
When Gems fuse, not only their bodies, but their minds as well, fuse into one. This creates an entirely different entity, as opposed to two minds sharing a single body. Malachite and Stevonnie, however, were shown to have separate thoughts with the latter pair showing it is possible for one mind to take over the body.

Formation
Fusions are formed when Gems perform a synchronized dance. If successful, Gems transform into an amorphous mass of energy before fully forming the fusion. If unsuccessful, Gems will be ejected before finishing the entire transformation.

Appearance
Fusion Gems have the appearance of the two or more Gems they fused with. This means that the pigments, clothing, weapons, hair, and overall body shape of the Gems are combined into one general look (the appearance of a fusion changes slightly every time they fuse). Also, each of the gemstones appear in the same locations of the Gems they fused with, such as Opal having gemstones on her head and chest; Sugilite having gemstones on her hands and chest; and Alexandrite having gemstones on her head, chest, and hands. Each Gem involved in the fusion often contributes an additional pair of arms. Prime examples are the fusion Opal from "Giant Woman" and Sugilite from "Coach Steven," who both have two pairs of arms, and Alexandrite, who has six arms. Many statues of Gems with multiple pairs of arms are seen in or depicted on ancient temples that belonged to the Crystal Gems, showing that multiple pairs of arms are a common trait among fusions. However, Garnet does not display extra arms, so the appearance of extra limbs may indicate some instability in the fusion. Another common trait among fusions is having more than two eyes.

Culture

 * The Crystal Temple has the appearance of a typical fusion.
 * In "Jail Break," Jasper derides fusion as "cheap tactic to make weak Gems stronger," while Garnet states she is a symbol of love.
 * Pearl implies fusion is rather intimate in "Coach Steven" and "Alone Together"; she tries to cover Steven's eyes while Garnet and Amethyst performed their dance, and says Stevonnie might be considered "inappropriate."

Abilities
Fusions are large, and significantly more powerful. They incorporate the powers, strengths, appearances, weapons, and abilities of both Gems.

Weapon(s)
Fusions wield their weapon(s), but can combine them into a singular, powerful weapon. These weapons typically harness the abilities of the weapons that were fused. A prime example being Opal's weapon, a longbow. Pearl's spear not only makes up the longbow, but the arrows are visually similar to the energy blast the spear can emit. Meanwhile, Amethyst's whip merely acts as the bowstring.

One-half

 * Stevonnie
 * Steven
 * Connie

Double

 * Garnet
 * Ruby
 * Sapphire
 * Opal
 * Pearl
 * Amethyst
 * Malachite
 * Lapis Lazuli
 * Jasper

Triple

 * Sugilite
 * Ruby
 * Sapphire
 * Amethyst

Quadruple

 * Alexandrite
 * Ruby
 * Sapphire
 * Pearl
 * Amethyst

Trivia

 * First demonstrated in "Giant Woman," as of "Jail Break," all known Gems except Peridot, Yellow Diamond, and Rose Quartz have been shown to fuse.
 * The dance used to fuse is a mixture of both Gems' dancing styles, which are based on their personalities.
 * Only six fusions are currently known: Garnet, Sugilite, Opal, Alexandrite, Stevonnie, and Malachite.
 * Stevonnie is the only known hybrid-fusion.
 * There have been four successful dances, and one failed dance.
 * The first successful dance was performed by Garnet and Amethyst, forming Sugilite.
 * The second successful dance was performed by Steven and Connie, which formed Stevonnie.
 * The third successful dance was performed by Ruby and Sapphire, which had formed Garnet.
 * The fourth successful dance was performed by Lapis Lazuli and Jasper, successfully forming Malachite.
 * The first failed dance was between Pearl and Amethyst, when they attempted to form Opal.
 * There were multiple potential dances shown in "Alone Together," but the only attempted dance was between Steven and Connie.
 * The fusion on the Crystal Temple has five gemstones, and has the most of any fusion shown thus far.
 * Forehead/Pearl
 * Chest/Amethyst
 * Palms/Garnet
 * Naval/Rose Quartz
 * It also has the most arms, but some are missing. If they were still intact, there would be eight.
 * The "Fusion Dance," displayed by gems, is very similar to the Fusion Dance shown in "Dragon Ball Z." However, the gems actually dance to fuse, rather than complete a set of poses like the Fusion Dance in Dragon Ball Z, in order to become one.
 * Fusion Gems can be separated by suffering heavy damage (Sugilite), or when one of the Gems fused disagrees with the other (Opal and Alexandrite).
 * Stevonnie seems to be an odd exception, since they separated while they were dancing in an attempt to embarrass Kevin.
 * Malachite is the only fusion gem to display two personality that fight (disagrees) each other and remain fusion, since the instability of a personality in the fusion because its end.
 * It is unknown whether or not Stevonnie, Malachite, and Alexandrite have signature weapons.
 * Malachite is the only fusion with two chests, four legs, and four eyes.
 * Alexandrite is the only fusion with six arms and two mouths.
 * Alexandrite is one of the only fusions whose dance wasn't shown.
 * Fusions can be made with humans, as shown in "Alone Together."
 * Although, this could be an ability exclusive to Steven, due to him being half-human and therefore "organic."
 * With the exception of Malachite and Alexandrite, all fusions are voiced by musicians, Garnet by Estelle, Opal by Aimee Mann, Sugilite by Nicki Minaj, and Stevonnie by AJ Michalka.
 * Garnet is the only known fully stable fusion.
 * Fusions combine the complexions of the Gems that form them.
 * Some of the fusion theme's names corresponds combining or fusing.
 * Opal's is called Amalgam, which is the combination of two elements to form another.
 * Sugilite's is called Synchronize, which is to act as one, or in unison.
 * Malachite's is called Collusion, which is when two parties conspire together.
 * Garnet's is called Reunion, which is the act of reuniting.