what sort of gemsona would you assign me 🙈
HULLO! OMG I'VE BEEN WAITING FOR THIS OPPORTUNITY *cracks knuckles*
***Long post warning, lots of info-dumping ahead. TL;DR answers at the bottom
I have SEVERAL ideas, so at least you have plenty of options/inspiration! I'll include both the gem itself along with any appearances that are canon to SU to give you reference. We'll start where I feel like a lot of people (myself included) start: with your birthstone(s), Ruby & Onyx!
July birthstones are traditionally Ruby, but these days most months have a 2nd stone. So you could choose traditional Ruby or the newer Onyx! (unfortunately there are no canon Onyxes in SU that I'm aware of) Rubies in-show are common soldiers used as a lighter personal guard or for quick low-level missions. They're short, coming in at around 4ft tall. Their personalities vary, but some traits we see repeatedly in the show are that Rubies get distracted easy, are often forgetful, fairly naive/easily deceived, stubborn, rowdy, goofy, a bit hot-headed & loyal to a fault! The Rubies below are all wearing similar/same Homeworld uniforms, but even so you can tell all of them apart, either by gem placement, certain accessories, variants in their outfits/hair color/skin color, or by their personalities!
Next are gems that have canon concepts/appearances that fit your vibe: Starting out strong with Sapphire!
Sapphires are what we would consider Royalty & closely resemble Princesses. They're one of Homeworld's Aristocratic Gem types, used mainly for diplomatic affairs or for their Future Vision, an ability that allows them to see the most probable outcome of a situation. As far as I know, its assumed that all Sapphires have this foresight, but it can vary, like how Padparadscha can only see what was, not what will be (though her variance is caused by being off-color, a term used to describe Gems that differ from the Mould Homeworld has for them). Sapphires are the same height as Rubies (around 4ft) & personality-wise tend to be more reserved, quiet, thoughtful, introspective & have a diplomatic way of looking at things. They tend to be more compassionate than most Gems of their status & their Future Vision helps them easily draw conclusions or make plans/decisions.
Morganite:
Not much is know about Morganite in-universe, since she never had a canon appearance beside her concepts in the art book. The little bit we do know about Morganite is that she was the Owner of the Ruby & Pearl that make Rhodonite, & her role on Homeworld is being a designer for the Diamonds' palanquins. Morganites are assumed to be high status Gems, like Sapphires & Aquamarines, on account of the Morganite above owning a Pearl & having her own personal guard (both signs of high status on Homeworld). Based on the concept art, her height would be just above that of a Ruby or Sapphire ( probably around 4'6"-5'0" ft). Fun fact: irl Morganites, Aquamarines & Emeralds are just a few of the handful of gems that are part of the Beryl family!
Speaking of, the next Gem on my list for you is: Pearls!
Pearls are considered status symbols on Homeworld. Only Gems of a high Aristocratic status own Pearls, like Morganites & Diamonds. Though it's assumed that Pearls may also be gifted to a Gem that performs exceptionally well or accomplishes great feats for the Diamonds. The Pearl will typically be customized by or for the Gem she's being made for, either mirroring her owner's appearance or matching their aesthetic in some way. This is done in the Reef, a Pearl production center owned by White Diamond. Pearls are known to entertain by either singing or dancing for other Gems, and will typically hold items for their master by storing said items in the pocket dimension inside their gemstone, as well as provide other forms of utility or assistance for their owners (like if unpaid interns were immortal). It's assumed Pearls stand at around 6'0"-6'6" feet tall & are always portrayed with a slender or lanky body type. Pearls are refined, elegant, graceful (usually), intelligent, determined, dedicated, handy & can almost easily pick up any skill/hobby. Pearls all seem to have distinct personalities, but share many of the same traits listed above.
Lapis Lazuli (one of my personal faves):
Lapis Lazulis are used as terraformers sent from planet to planet by Homeworld during early stages of colonization to rebuild planets to be ideal for Gems to inhabit. Not much is know about their societal status, but they're very powerful Gems for how small their frame is. Lazulis are shown as shorter than Pearls but taller than Rubies, so they're presumable around 5'5"-6'0" tall. Personalities vary, but the few that we've seen have consistent traits of; stubbornness, being somewhat reserved, self-assured/confident, determination, fighting spirits, no-nonsense (at least at first impression) & can be judgy, but are also whimsical & friendly once they warm up. Their main abilities are flying with water wings that they make, hydrokinesis, & the ability to make ice.
An honorable mention of this category: Moonstone
Very little is known about Moonstones- even less than we know about Morganites -as all we have to reference her is the two photos above. The one thing we do know is that Moonstones have invisibility. These Gems are smaller in stature, but approximate height is unknown. This one makes me think of you based on the irl stone more than the SU version, but its in this category since there is visual canon references.
Lastly, there are a few stones that I associate with you just based on your personality & overall vibe. When I think of stones that are "you", these also come to mind! We have;
Opal (left)! Fascinating, colorful, a unique stone that is dazzling, stands out from most other stones & gives a fantasy/otherworldly vibe. The only canon Opal is a fusion, but we've learned that in-universe there are stand-alone Gems as well as the fusions (since fusions name themselves, they're not actually related to the stand-alone Gems)
Moldavite (right)! Gets a bad rap, is actually a really nice stone! Very unique in formation & the earthy dark green reminds me of you! To me, instead of cottage-core earthy vibes, Moldavite is more witchy, forest sorceress vibes.
Moss Agate/Tree Agate (respectively). Agates in-universe are typically big buff Gems, standing between 7-9ft tall. They're typically soldiers, guards, protective escorts or sent on missions that require lots of muscle. The SU Agate body type/personality may not fit you, but the stones above remind me of you because of the earthy/foresty aesthetic!
Lastly, one that I think of when I think of Gemsonas for you is Angelite! Mostly because of the angelic, ethereal feminine vibe I get from this stone.
As promised, the TL;DR: If you were to ask my humble & professional opinion as someone who loves rocks & loves Steven Universe, my personal opinions on stones that would suit you best for a potential Gemsona (out of the 13 I listed) are; Moonstone, Pearl, Morganite, Angelite, Lapis Lazuli, or Opal.
Don't let my opinion sway you on what you want the most though! And don't let the canon designs deter you from choosing one that really speaks to you! Many people's FanGems look completely different from the canon versions. Same goes for what the Gem's job is or what their personality is like. At the end of the day, a Gemsona/Gem OC is yours to play around with, & with that you have the freedom to do whatever you want with them forever!