Disclaimer: I am not trying to prove that this theory is correct. I am simply pieceing information together that could make this theory true. This is just a theory, and I could be completely wrong.
I will be discussing if it is possible that Jasper is not a "perfect" Quartz soldier, but instead a "perfect" Cluster Gem. Jasper could be a forced fusion of two Gems who's gemstones were not shattered, but instead forced together while completely intact, unlike other Cluster Gems seen. If Jasper is a forced fusion of two Gems, I believe they are defective Quartz soldiers. Gems of the same type are identical (except for slight variation in their color palettes and sometimes outfits). I'm certain that the fusion of two defective Quartz soldiers would look similar to a singular Quartz soldier of a different type that is not defective. It has also been confirmed that singular Gems have their fusion counterparts. If Jasper is a forced fusion of two Gems that are completely intact, I believe Steven's healing spit would be able to separate her components' gemstones. Jasper would most likely be unaware of her status as a fusion because Pearl confirmed that Gems "loose themselves" if they stay fused for too long in "Coach Steven", and Jasper wouldn't be able to unfuse due to being a forced fusion. I also want to add that both Garnet and Rose Quartz were revealed to have hidden identities (Garnet was reveled to be a fusion, and Rose Quartz was reveled to have been Pink Diamond), so if Jasper is a forced fusion, she wouldn't be the first character to have a hidden identity.
Possible Foreshadowing to Jasper Being a Forced Fusion
- Jasper's gemstone is very different from other Jaspers shown.
- It has a similar appearance to a Cluster Gem's gemstone, and the way it is shaped makes it appear more colorful than other Jasper gemstones.
- Jasper's exit hole was shown in "Beta", but it was only assumed to be: Steven says "This is Jasper's hole?" After that, Amethyst and Peridot assume it is as well. Also, the hole's size seems to be a lot larger than Jasper. Character heights are inconsistent, but Jasper is shown to be a lot smaller than her hole's size.
- Fusions shown have had less than the combined amount of their components' body parts, but not more. Both Lapis and Jasper have two arms, but Malachite has six.
- Jasper's character revolves around fusion.
- Jasper has been defeated by several fusions on multiple occasions.
- Garnet in "Jail Break"
- Malachite from "Jail Break" to "Super Watermelon Island" (Lapis was able to overpower Jasper and keep their fusion at the bottom of the ocean)
- Alexandrite in "Super Watermelon Island"
- Stevonnie in "Crack the Whip"
- Smoky Quartz in "Earthlings"
- The Corrupted Jasper Fusion in "Earthlings" (the Snow Monster was strong enough to unfuse with Jasper)
- In "Alone at Sea", she asks Lapis to Malchite with her again, and admits to being wrong about fusion (she said that it was a "cheap tactic to make weak Gems stronger" in "Jail Break").
- In "Earthlings", she was upset for a brief moment about no one wanting to stay fused with her.
- Fusion is what ultimately lead to her corruption.
- Jasper has been defeated by several fusions on multiple occasions.