The Great Diamond Authority

"Each Gem is made with a purpose: To serve the order of the Diamonds. Those who cannot fit inside this order must be purged!"

The Great Diamond Authority is the matriarchal body of Gem leaders who rule in absolute power over the Gem Homeworld and all still-existing Gem colonies.

Symbol
The symbol of the Great Diamond Authority appears on many Gem structures and has changed over time. On structures mostly built before the Rebellion, the symbol consists of four diamond shapes: White (top), Yellow (left), Blue (right), and Pink (bottom). On modern structures, as well as on the partially-healed Centipeetle Mother's drawings that are seen in "Monster Reunion", the Pink Diamond symbol has been removed, leaving only the White, Yellow and Blue symbol shapes (now depicted in the form of overlapping triangles).

Yellow Diamond
Yellow Diamond is one of the Diamond leaders. She is the current superior of Jasper, former superior of Peridot, and also the current superior to countless other Gems "made" for her. She commenced the Cluster project to acquire it as a geo-weapon after Earth was deemed unfit to be a colony due to the rise of the Crystal Gems.

According to Peridot in "Hit the Diamond", Yellow Diamond is in complete control of the Gem Homeworld's military.

Almost all of her subordinates (except her Pearl, Doc and Navy) have a small Yellow Diamond insignia on their chests in two symmetrically connecting diagonal black lines.

Subordinates

 * Peridot (formerly)
 * Jasper (originally Pink Diamond's subordinate)
 * Yellow Pearl
 * Rubies
 * Ruby (Doc)
 * Ruby (Eyeball)
 * Ruby (Army)
 * Ruby (Navy)
 * Ruby (Leggy)

Blue Diamond
One of the Diamond leaders. She was the superior of Ruby and Sapphire, and many other Gems "made" for her. She was the supervisor of the colonization of Earth. Her subordinates used to have a large blue diamond on their bodies but now they have a similar design to Yellow Diamond's subordinates, with a small light Blue Diamond insignia on their chests in two symmetrically connecting diagonal dark lines.

According to Rebecca Sugar, blue-colored Gems are oriented towards diplomatic roles.

Subordinates

 * Sapphire (former court member)
 * Several Rubies
 * Ruby (formerly)
 * Blue Pearl
 * Holly Blue Agate
 * Unknown court members
 * Several former subordinates of Pink Diamond
 * Amethysts
 * Jaspers
 * Carnelian

Unknown White Diamond
One of the Diamond leaders. Details about her are unknown except her white symbol that appears alongside those representing Blue Diamond and Yellow Diamond on both ancient and modern Gem structures. Her name is never stated, but due to consistencies and naming patterns, it is most likely White Diamond.

She appears to have spiky hair and her gemstone is placed on her forehead according to her mural. Also, according to her mural, she had the most Gem Colonies when the Moon Base was built. However, it is unknown how many she has now.

Pink Diamond
A former Diamond leader. Details about her are unknown other than that she was in charge of the Earth colonization and occupation efforts, and that her symbol is present on the majority of ancient Gem structures, but absent on structures dating as early as the Pyramid Temple, as she was shattered by Rose Quartz, one of her former subordinates, at some point during the Rebellion. She also has a mural in the moon base, along with all the other Diamonds.

Pearl's space suit, as seen in "Space Race" and "Back to the Barn", has the Pink Diamond insignia on its chest. This implies that Pearl was somehow previously involved with Pink Diamond before her destruction. Sardonyx also sports pink diamonds on her feet, and this most likely comes from Pearl.

According to Eyeball in "Back to the Moon", Pink Diamond was shattered by Rose Quartz. In the following episode "Bubbled", Garnet confirms that Rose did shatter Pink Diamond. This likely occurred between 6,250 and 5,750 years ago, taking into account that Jasper (who, as explained by Peridot, was created halfway or so through the war) had been originally assigned to her, that Blue Diamond was in charge of the Earth colonization efforts 5,750 years ago (when Garnet first formed), that Centipeetle drew only 3 diamonds when recounting the end of the Rebellion (which happened more recently than 5,300 years ago, when Bismuth was bubbled), and that the Rebellion took place over roughly 1,000 years. Pink Diamond also owned a human zoo which she used to store humans to showcase as trophies of her conquests.

Past Subordinates

 * Rose Quartzes
 * Rose Quartz
 * Bubbled Rose Quartzes
 * Amethysts
 * Jaspers
 * Jasper
 * Carnelian

Influence
The Great Diamond Authority has great influence on Gems of lower castes and members of their courts. Most Gems serving under a Diamond wears a diamond emblem on their outfit. The color of the diamond emblem worn by followers depend on the Diamond. Members of a Diamond's court are known to show respect, such as Sapphire calling Blue Diamond "[their] Diamond". Some members are passionate and enthusiastic about working for a Diamond. For example, Peridot once exclaimed, "I would never forsake the Gem I was made for!", and Holly Blue Agate who goes on about how great Blue Diamond is. Gems who serve under the Diamonds will do anything to avenge their Diamond, as seen in Jasper's case in "Earthlings", and later with Eyeball in "Bubbled". But it's also show that if a Diamond is shattered it will be covered and kept in secret, as any history of Pink Diamond and The Rebellion were hidden by the other Diamonds from any Era 2 Gems, as Peridot didn't knew anything about The Rebellion when she was assigned her mission on Earth, and every defective Quartz that previously served under Pink Diamond was put to work in her Zoo in secret.

Transportation
For an overview of the different Diamond transportation methods, click here.

Trivia

 * The confirmed instrument of the diamonds is a synthetic sound combining harmonette and strings, processed by a synth, this can also be heard in Same Old World and Monster Reunion when the Corrupting Light flashes.
 * The current symbol might be a reference to the Triforce symbol from The Legend of Zelda, as they both are three connecting triangles that form a symbol.
 * The former symbol resembles the NFPA 704 diamond symbol, with slightly different colors (one of the diamonds is red instead of pink) and with the colors' positions switched.
 * The former symbol's order of colors seems to represent the location of the gem in the body of its owner: both Blue and Yellow Diamond have their gem in their chests, so they are equal in position in the middle row, whereas White Diamond has her gem in her forehead and Pink Diamond has it in the lowest position in her navel, hence in the symbol White Diamond is on the top and Pink Diamond is on the bottom.
 * The Great Diamond Authority was yet another of Ronaldo Fryman's paranormal theories that was proven true.
 * He claimed his theory in the first season episode "Keep Beach City Weird", and Peridot confirmed the matriarchs' collective name in the episode "It Could've Been Great".
 * It is revealed in "Monster Reunion" that the Diamonds were the ones responsible for the corruption of almost all remaining Gems on Earth.
 * Centipeetle only drew three diamond symbols when she was asked who or what caused the damage to her and the other Corrupted Gems, so one of the Diamonds was not involved with this weapon, presumably Pink Diamond, who was shattered during the Rebellion, while the damage was caused at the end of it. Centipeetle's drawing depicted the original symbol of adjacent diamonds (with Pink Diamond's removed) rather than the modern symbol of overlapping triangles.
 * The circles placed behind the heads of the Diamonds in their murals strongly resemble halos, a common motif in the sacred art of Ancient Greece, Ancient Rome, Hinduism, Buddhism, Islam, and Christianity.
 * So far, White Diamond is the only diamond that has not been mentioned by the characters in the entire series, being only depicted in an indirect way.

Gallery
Autoritatea Diamantelor