Cristal Gems

The Crystal Gems, also referred to as the Rebels, are a group of Gems established by Rose Quartz who, unlike the rest of their kind, seek to protect the Earth instead of exploiting it and are the self-proclaimed guardians of humanity. Their title as the "Crystal Gems" distinguishes them from the Homeworld Gems.

Members

 * Garnet: The de facto leader of the group and a fusion Gem who wields a pair of gauntlets, later with brass knuckles added. She joined the Crystal Gems after deciding to stay a permanent fusion and meeting Rose Quartz. She is the brawler of the group, using her gauntlets to inflict destructive attacks.
 * Ruby: A short-tempered Gem who makes up half of Garnet. She wields a maroon gauntlet. Initially a low-level Homeworld Gem soldier, she was to be destroyed for accidentally fusing with Sapphire, but was saved by her and stranded on Earth. She joined the Crystal Gems after deciding to stay permanently fused as Garnet.
 * Sapphire: A calm, yet distant Gem, and the other half of Garnet. Any weapon aside from her future vision has not been seen. Initially a member of Blue Diamond's court, she defected to protect Ruby and joined the Crystal Gems after deciding to stay permanently fused as Garnet.
 * Amethyst: The carefree member of the group who wields a one-to-three-tailed whip with morning stars on the end. Unlike the other Crystal Gems (besides Steven, who is also from Earth), Amethyst was made on Earth, in the Prime Kindergarten.
 * Pearl: The intellectual and precise member of the group who wields a spear. She and Rose were the first members of the group.
 * Steven Universe: The half-human and youngest member of the group who has healing saliva, and can summon a pink shield and bubble. He is the son of Rose Quartz, the founder of the Crystal Gems, who gave up her physical form to give birth to him. After growing up in the care of his father, he began living with the Crystal Gems as a member in his adolescence.
 * Peridot: The maturing, curious, and stubborn one of the group. She is a natural-born technician and a certified Kindergartner. She was once an enemy to the Crystal Gems, but was officially accepted into the group after disobeying Yellow Diamond in "Message Received". Unlike the other Crystal Gems, Peridot does not live at the Temple, but rather the Barn. Due to her natural-born skill in engineering and constructing, she is considered to be a technician and engineer of the group like Pearl.
 * Bismuth: A weaponsmith of the Crystal Gems from the Rebellion era more recently brought to light. Rose showed her she could follow her own wants, but when that included shattering Gems, Rose poofed and bubbled her. She's currently bubbled in the Burning Room due to her battle with Steven over the same issue. As stated by herself, her power is equal to Garnet.
 * Connie Maheswaran: Steven's human friend and ally. Connie practices swordsmanship (since "Sworn to the Sword"), because she wants to join Steven, to protect him and preserve his legacy. In "Rocknaldo", Steven confirms her place as a member of the group.

Crystal Gem Fusions

 * Opal (revealed in "Giant Woman"): A four-armed, tall and slender Gem who wields an energy bow. She is the fusion of Pearl and Amethyst.
 * Sugilite (revealed in "Coach Steven"): A gigantic and bulky Gem who wields a flail. She is the fusion of Garnet and Amethyst.
 * Sardonyx (revealed in "Cry for Help"): An upbeat and charismatic Gem who wields a war hammer. She is the fusion of Garnet and Pearl.
 * Alexandrite (revealed in "Fusion Cuisine"): An extremely tall, six-armed fusion with an extra mouth that can emit flames. She is the fusion of Garnet, Pearl, and Amethyst.
 * Stevonnie (revealed in "Alone Together"): A tall, one-quarter-Gem and three-quarters-human fusion. They are the hybrid fusion of Steven and Connie.
 * Garnet: A tough, mysterious, and very stable fusion. Confirmed in "Jail Break", she is the fusion of Ruby and Sapphire.
 * Rainbow Quartz (revealed in "We Need to Talk"): A tall, slim, and acrobatic fusion. She is the fusion of Rose Quartz and Pearl.
 * Smoky Quartz (revealed in "Earthlings"): A medium, chubby jokester who wields a large yo-yo. They are the fusion of Steven and Amethyst.
 * Unknown Fusion Gem: Not much is known about this fusion. She appears to have large, curly hair and four arms. She saved William Dewey and Buddy Buddwick from the Unknown Giant Gem Monster, and helped them find landcenturies ago.

Former Members

 * Rose Quartz: Steven's mother, and the former leader and founder of the Crystal Gems who believed all life is precious. She gave up her physical form so that Steven could be born.
 * "Crazy Lace" (mentioned by Bismuth)
 * "Biggs" (mentioned by Bismuth)
 * "Snowflake" (mentioned by Bismuth)
 * Other Amethysts (mentioned by Bismuth)

Allies/Companions

 * Lion: A magical lion that became Steven's pet in "Steven's Lion", but was revealed in "Lion 3: Straight to Video" to have a connection with Rose Quartz, which was explored more in depth in "Rose's Scabbard".
 * Greg Universe: Rose Quartz's lover and Steven's father. He knew the Crystal Gems when he was a young adult and currently supports them mostly to be a part of his son's life ("Laser Light Cannon", "Ocean Gem", "House Guest", "The Message").
 * Lapis Lazuli: Lapis became Steven's friend in "Mirror Gem", and convinced Steven to let her free. During that episode and "Ocean Gem", Lapis and the Crystal Gems fought. Lapis later became an ally by warning the group about Peridot and Jasper, saving them by trapping Jasper in their fusion, Malachite. Months later the Crystal Gems are reunited with her after Alexandrite split Malachite apart. She is now friends/roommates with Peridot at the Barn. In "The New Crystal Gems", she is declared a member of "The Crystal Temps".
 * Pumpkin: Pumpkin is the sentient pumpkin pet of Peridot & Lapis Lazuli created by Steven in the episode "Gem Harvest". It stood in as Pearl in "The New Crystal Gems" in the team of "The Crystal Temps" with Peridot, Lapis, and Connie Maheswaran.
 * The "Famethyst": Quartz soldiers from Earth-stationed in Pink Diamond's Zoo. They befriended Amethyst and assisted the Crystal Gems in escaping the facility in "That Will Be All".
 * Ronaldo Fryman: A Beach City resident interested in the odd occurrences around him. He attempts to join the Crystal Gems in "Rocknaldo" going by the name "Bloodstone" after gaining an admiration for their cause. After misunderstanding what it means to be a Crystal Gem, he decides to work alone to educate people about the group by making pamphlets about the Crystal Gems.
 * Topaz: A Homeworld fusion of two Topaz Gems. After Steven gave his speech to Lars, Topaz was moved by their relationship and tried to help them out. However, Aquamarine was quick to stop her, reminding her that once they returned home, she would be separated and shattered for rebelling.
 * Lars Barriga: Aboard Aquamarine's Ship, Lars was taken to Homeworld with Steven. Once they were bought back together again during Steven's trial, they escape via Blue Diamond's palanquin, and hide with the Off Color Gems. However, the Robonoids find everyone, and are out to shatter the Off Colors and Steven. Luckily, Lars helps out by fighting back against them, but unfortunately dies after getting hit point blank with the explosion of the last Robinoid, getting smashed against a wall, and falling from a great height. After Steven accidentally revives him with a tear, Lars undergoes a magical change. He decides to sacrifice himself by letting Steven go back to Earth through his hair, as Steven promises to find a way to get him back home.
 * Off Colors: After Steven and Lars land on Homeworld, they encounter a group of unaligned Gems, outcasted from Homeworld society for being abnormal, defective, permafusions, or in Padparadscha's case, having botched abilities. After befriending Steven and Lars, the Off Colors are willing to give up their Homeworld ways and come to Earth, but they stay with Lars for the time being while Steven finds a way to get him home.

History
Much of the history of the Crystal Gems is shrouded in mystery. What is known is that several thousand years ago, Homeworld Gems arrived on Earth and created the "Kindergarten", a facility used to mass-produce new Gems via Injectors. This process was very invasive and damaging to the planet; the gestating Gem draining the life force out of the surrounding area in order to grow. According to Pearl, if this process was allowed to continue, the present Earth would be a lifeless, barren wasteland. Rose Quartz's empathy towards the Earth and beliefs on the Kindergarten's injustice instigated a rebellion fought by those who would become known as the Crystal Gems. Little is known about the ensuing war, simply known as the Rebellion, other than that it ended with all but a few of Rose's closest friends being destroyed, and the Homeworld Gems being driven off Earth, which was then cut off from Gem-controlled space by destroying the Galaxy Warp. For about 5,500 years, the remaining Crystal Gems used their abilities to defend Earth from countless Gem-based threats. However, Rose, as a great admirer of humanity, gave up her physical form to give birth to a half-human child, Steven Universe. The other remaining Crystal Gems (Garnet, Amethyst, and Pearl) have taken it upon themselves to raise him alongside Greg and teach him how to use his powers.

In "On the Run", it is revealed that Pearl and Garnet originally came from the Gem Homeworld, while Amethyst was formed on Earth in the Prime Kindergarten.

Despite being defeated thousands of years ago, the Homeworld Gems have shown renewed interest in Earth, first sending the Red Eye (which was promptly destroyed) to scan for surviving Gems and, as of "Warp Tour", sending one of their engineers, Peridot, and her robonoids to fix the Galaxy Warp, as well as reactivate dormant Gem technology left on Earth, such as Facet Five in "Marble Madness" to check on the Cluster.

Rose Quartz and Pearl were shown to be the original members of the Rebellion (as told in "The Answer"). Before Garnet joined the Crystal Gems, the Rebellion has been happening for quite some time, enough for Pearl to gain a reputation as "terrifying renegade" and that the service of a seer Sapphire was required. When Ruby was slated to be executed due to changing the future and letting the traitors escape by fusing with a high-level gem, Sapphire saved her and the two of them decided remain as Garnet and join the Crystal Gems. Sometime after the war, Amethyst is found and taken in as a member. Rose Quartz eventually gives up her physical form to bear a half human, half-Gem being named Steven Quartz Universe. Peridot, a Gem loyal to Homeworld, betrays her superior Yellow Diamond in "Message Received" as Peridot believes Yellow Diamond is too irrational, contrary to her previous beliefs. This action allows Steven to dub Peridot a Crystal Gem with Garnet, Amethyst, and Pearl in agreement.

Living Space
The Crystal Gems evidently own a section of Beach City's shoreline, on which the Crystal Temple and Steven's Beach House resides. Lapis Lazuli and Peridot currently live in the Barn which resides on a hill outside of Beach City. The Barn belongs to Greg and his cousin Andy, but the Gems have effectively taken ownership, using it as a house for new members and to build any required machinery such as The Universe Mach 3 and the Gem Drill.

Transport
Though technically belonging to Steven, Lion occasionally acts as transportation for the Crystal Gems to places they cannot warp to, such as the Moon Base. As of "Bubbled", they owned a Roaming Eye ship that the Rubies left behind, but it was stolen back by Navy in "Room for Ruby". They have also used the Gem Sloop for traveling at sea, though it hasn't been seen since "Cat Fingers".

Physical Weaponry
Unbeknownst to Garnet, Amethyst, Peridot, Lapis Lazuli, Bismuth and Greg, they also have access to an Armory containing more Laser Light Cannons and other various weaponry. They also have a Forge which is currently unusable as their blacksmith, Bismuth, is currently poofed and bubbled to prevent her from harming herself and others.