How Gems on Earth became Corrupted
Theory Information
Author Spyair123
Illustrator Spyair123
Date of Publication May 20th, 2016
Publication Order
Previous How and Why Homeworld started doing Fusion Experiments
Next Gem's Skin Color


This theory is going to explain how the rebellion ended and how gems become corrupted.


In the episode "Same Old World", we finally get to see Lapis Lazuli's backstory and how she was trapped and abandoned on Earth. In the episode we saw that the Homeworld gems were panicking to escape Earth and retreating back to Homeworld, and then after they left, a bright light that comes from space illuminates the Earth.

How the Rebellion Ended


When it came clear to the Diamond Authority that the Earth is no longer a viable colony, the Homeworld gems finally gives up on the war and used the Earth for fusion experiments and ultimately destroy it. The Diamond Authority notified their followers that they will wipe out every gem on Earth and it made the Homeworld gems panicked to immediately flee. After all of the Homeworld gems fled from Earth, the Crystal Gems finally declared that they have won the war against Homeworld.

How the Gems became corrupted

But the records say that gems were wiped out on Earth!

—Peridot, Marble Madness
Remember the bright yellow, white, and blue light that illuminated Earth? I think that's the reason why gems become corrupted. My guess is that the blast is what caused all of the Crystal Gems on Earth to become corrupted. So you're probably wondering, why didn't Rose Quartz, Pearl, Garnet and Amethyst become corrupted?

Remember in the episode "The Return", Greg mentioned that Rose Quartz could've only saved a handful of her friends if it weren't for her shield. Pearl and Garnet must've been with Rose Quartz at that time when the blast occured. Rose Quartz saw the blast coming and protected Pearl and Garnet using her shield, while the other gems on the face of the Earth were hit by it and become corrupted. Amethyst was probably still incubating in the Kindergarten when this had happened.


Homeworld had lost hope on stopping the war on Earth and decided to use for a series of fusion experiments. The Homeworld gems on earth must've been alerted by the Diamond Authority that they plan to wipe out every gem on Earth, and hearing this, the Homeworld gems panicked on escaping Earth. After all the Homeworld gems had left the Earth, Homeworld blasts the Earth, and presumably that's what's caused gems to become corrupted.

Confirmed Theory

In "Monster Reunion", the Diamonds did, in fact, corrupted Gems on Earth to end the Rebellion. And everything else was in fact true too.