The locations of Kindergartens are mainly selected based on the material making up an area; areas with richer resources will create standard Gems while areas made up of lesser resources will create Gems with defects. Once a location is chosen, the area is altered by Gems so that Injectors are able to be placed upon the walls of the location. As the name implies, these Injectors will inject goo into an empty space on the wall. The goo will then drain its surroundings of its life force in order to grow and develop. Once a Gem is fully grown, its gemstone will harden and the Gem pops out of the wall, leaving behind an exit hole.
Because there are so many types of the same Gem, Homeworld created a system where Gems are given a code to identify themselves. This code is based on the Kindergarten where the Gem was made. For example, if Amethyst was a part of Homeworld society, she would be known as Amethyst Facet-5 Cut-8XM. Facet 5 is there because that is where the Prime Kindergarten is located (Amethyst was made there), and 8XM is the name of the spot where her exit hole is located. According to Peridot, the code given to exit holes go from top to bottom, so if 8XJ was at the top of the wall, 8XK would be beneath her, and so on.
Variables Which Alter Gems
There are many variables which alter a Gem's appearance when they emerge from a Kindergarten:
- Prolonged incubation: If a Gem remains incubating in the ground longer than they are supposed to be, they will emerge shorter than they are supposed to be. Amethyst is a notable example of this.
- Material in surrounding area: Certain spots where goo is inserted into the planet may be made of different material than other areas of the Kindergarten. This can cause a Gem's physical form to have certain characteristics. For example, Peridot was able to tell that Amethyst Facet-5 Cut-8XJ had curly hair based on the iron deposits in her exit hole.
- Geography: The Beta Kindergarten was set up in a location where there were lumpy hills made of sandstone. Because Homeworld did not take the time to properly alter the geography to their needs, Gems emerging from the deformed land came out defective. Only Jasper came out properly because of the frictional rock melt and glass located at her exit hole.
The establishment of a Kindergarten saps the life force from its surroundings. When a colony is completed with multiple Kindergartens established globally, organic life becomes extinct on that planet. Even though the colonization of Earth was never completed and only two Kindergartens were established on the planet, life has still been unable to reestablish itself where they are located, thousands of years later.
Known Kindergarten Facilities
- Prime Kindergarten, located on Earth in Facet Five
- Beta Kindergarten, located on Earth in Facet Nine
- Homeworld Kindergarten, located in an abandoned area of the Gem Homeworld
- Zeta Kindergarten, which is alluded to in Save the Light when Peridot calls Squaridot a "Zeta Kindergarten Clod". Other details about this Kindergarten, such as its location, are unknown.
- Delta Kindergarten, which is appeared in The Phantom Fable.
- "Kindergarten" means "children's garden" in German and it usually refers to a place of preschool education. In this case, it literally means a garden where 'children' are grown. In "Know Your Fusion", Sardonyx makes a reference to the former, joking that "[Jasper] should've gone back to preschool!"
- The person-shaped holes on the sides of the Kindergartens, as well as the manner in which Amethyst slid into hers, appear to be inspired by the Junji Ito horror manga, The Enigma of Amigara Fault.
- The Injectors resemble bacteriophages. This alludes to the fact that when a bacteriophage or just any virus invades another cell, the cell will just create more viruses until it is destroyed, much like how when a gem is inserted into the ground by the injector, the ground will become barren and lifeless.
- The body of the Injector rig encases a structure that resembles an organic heart, which is attached to the head and feet via red and blue tubes resembling arteries and veins, respectively.
- As revealed by Peridot in "Too Far", Gems that stay in the ground for too long have stunted height when fully grown. An example of this would be Amethyst.
- In "Beta", Peridot revealed some details that make a quality Kindergarten/Gem hole.
- The surfaces must be flat (curved surfaces result in Gems emerging sideways).
- The holes must have even spacing and consistent depth.
- The Gem must not come out of the hole at an angle and leave a strong clean silhouette.
- Exceptionally good quality holes have frictional rock melt, and glass all the way to the back.
- "Now We're Only Falling Apart" marks the first time Gems are seen emerging from a Kindergarten. First, a section of cliff face begins to glow brightly in the shape of the emergence hole before bursting open, allowing the Gem to exit.
- The majority of Kindergartens are named after letters of the Greek Alphabet. Beta is the second letter, Delta the fourth, and Zeta the sixth. Interestingly, the first Kindergarten on Earth is referred to as the "Prime Kindergarten" and not "Alpha Kindergarten."