Tommy: Yellow Diamond is the diamond overseeing Xen’s colonization. He is fully aware of the Cluster experiments and is disgusted by them. However, Blue Diamond insists that the labs stay on his colony, so Yellow tries to avoid them at all costs. He feels incredibly awkward about the diamond salute and how gems treat him, so he shapeshifts into a Citrine quartz whenever he decides to look around the base, and he writes special pardons for himself so his own security don’t throw him out. He stays in his Citrine form up until the betrayal, where he then shows his true form and ends up destroying the physical forms of every guard in the room, along with Kyanite. Rainforest Jasper makes a run for it while holding onto Kyanite’s gem, but ends up losing it along the way. Yellow Diamond then sends out a shockwave across the facility, and many of the gems still in the facility end up getting corrupted.

Gordon: Spessartite Garnet that was in charge of the experiment regarding the Xen Crystal. The other Garnets in the facility would often refer to him as “Half-Baked” due to the fact that he came out of the ground prematurely, and this led to him being generally airheaded. He’s still a good leader, but just not as smart as the average Garnet. He’s actually pretty fuckin’ dumb. During the betrayal, his physical form is destroyed and his gem gets cracked. The crack worsens overtime, and he nearly gets shattered before he meets Amber.

Coomer: Rainforest Jasper is one of the quartzes assigned in Black Mesa. Once a perfect soldier, Jasper’s gem was chipped during the explosion following the Crystal Experiment. Occasionally, his physical form with “Glitch” and his psyche will reset, always greeting the Highest-Ranking gems in the room. As far as he knows, Garnet is the highest-ranking amongst all of them. (Hello, Garnet!) After the betrayal, he finds his fellow Jaspers (all of whom are corrupted) and suffers a mental breakdown.

Bubby: Kyanite was specifically made for overseeing experiments in Black Mesa. His intellect is unmatched, and he knows the Research Facility like the back of his gem. He firmly believes that Garnet is responsible for the failed experiment, which is why he leads him into a trap. Kyanites are actually much taller than our dear scientist. This is because Kyanite himself is several Kyanite shards melded together. When an uncorrupted Quartz finds his gem, he is placed into a prison to be questioned later on. 

Benrey: A Quartz soldier whose conscience is connected to the cluster. Every time he gets shattered, another cluster experiment gains sentience, and is used as a puppet. Once the Science Team breaks out of Black Mesa and finds themselves on the surface of the Alien Planet, they finally get to see The Cluster. He follows them around until they finally get to the galaxy warp, only to find it’s been overrun with Xen Fauna, and that The Cluster is guarding it. Benrey is aware that Citrine is actually Yellow Diamond from the very beginning, as he can sense it a mile away. He even calls Citrine “Yellow” and “My Diamond” just to spite him.

Darnold: Amber is a gem who specifies and the creation of synthetic materials, such as the liquid used to repair Warp Pads. He was in the middle of an experiment which uses Diamond essence to bring shattered Gems back to life. When Amber and Garnet meet, Garnet’s crack has worsened considerably, and is almost to the point of splitting in half. Amber decides to use his experiment to heal Garnet’s gem. The concoction leads to Garnet’s gem being healed, but it also leads to more crystallization than necessary. Garnet’s gem now is sticking out somewhat, which materializes in the form of his right hand becoming versatile and easy to shapeshift. He can fire small, but painful sparks out of his right hand, serving as a mini-gun.