So by now a lot of people have noted that gem locations and gem personalities are linked. Below I’ve compiled a list of how a gem’s personality is linked to their gem placement. This may lead us to predict traits of certain gems before we get to know them.

Forehead (Pearl and Peridot): Forehead gems seem to more intellectually-oriented and both Pearl and Peridot show symptoms of Asperger’s Syndrome

Eye (Eyeball/Rubeye, various monsters): The one eyepatch gem we’ve seen was grim and mysterious. Both are classical personality traits of “the grizzled veteran”

Nose (Jasper): The only nose gem we’ve seen, Jasper, is both literally and figuratively “Hard Nosed”

Collar (Yellow and Blue Pearl): The collar, in the sense of a dog collar, symbolizes a lack of self-possession or ownership. The two gems with collar gems we’ve seen are both pearls, a slave caste who both appear loyal to and fearful of their masters.

Chest (Amethyst, Yellow and Blue Diamond, Doc, Bismuth [citation needed]): Chest gems are emotional and quickly angered, with their gem located right over their heart.

Navel (Rose, Steven, Navy): Navel gems tend to be significantly more sensitive and feminine than normal. Understandable given that the navel, the scar left behind by the umbilical cord, is symbolic of a maternal connection and feminine influence

Back (Lapis Lazuli): The one back gem we’ve seen, Lapis Lazuli is unable to leave the past behind her and it always looking back at what she’s left behind

Left Bicep (Army): A sign of brute strength. Army was noticeably more quiet and muscular befitting the strong, silent type.

Palm of Right Hand (Sapphire): The palm is symbolic of love (holding hands) as well as taking matters into one’s own hands, and the right is associated with strength and influence (regarding her title) “doing the right thing” as sapphire did when she gave up her title for the gem who protected her

Palm Of The Left Hand (Ruby): The Left on the other hand is associated with counterculture and subversive behavior, such as Ruby breaking the taboo of mixed-gem fusion

Back of Left Thigh (Leggy/Nuby): The one gem we met with a leg gem was overly cautious and easily frightened. The gem placement may symbolize a desire to turn tail and run away

EDIT: I should probably mention something else:

Gem location symbolism does’t apply to most fusions, but the few it does apply to all have a singular trait in common: They lost themselves in the fusion

Both Hands: Garnet takes matters into her own hands and lets her fists do the talking

Both Hands and Chest: Sugilite is combines strength with emotion to get wanton violence

Back and Nose: Loss and wrath combine in Malachite to create a creature consumed by a desire for revenge against Steven

Okay, wow, that’s a big info dump, but what exactly do we do with this information?

The same thing we do every night Pinky; Speculate about children’s cartoons