He'd die, yes, but it could end up being a Disney Death if Pink/Rose regenerates as a result due to resurrection tears; that's something that could conceivably happen in the show, even if it would be kind of cheap.
That doesn't make sense though,what we eat becomes our body, not just half of it, I don't know whether steven could survive gem removal, he's not entirely human so maybe it plays the role of keeping it all together, maybe it is what gives him his life energy (does this make sense?) or maybe it replaced what humas use to regulate their body functions (why? because maybe it does the job better) and ripping it off would result in a state similar to brain dead.
I just don't think him (or his body) losing half of everything is the only possible result, but don't quote me on that; tho, if true, that would mean he would give all of his babys the same genes, barring for mutations, or be sterile because none of the genes from his gem side would survive separated from it.
@LSBK: With good use of Gory Discretion Shot / Bloodless Carnage they could pull off a Disney Death for Steven.
The idea of so many people being curious about Steven's died gem removal makes randomness feel positive...
Rules of the Internet 45. Rule 45 is a lie. Check out my art if you notice.Yeah, putting a hard line between the "physical" and "mental" ignores that thoughts are created by a physical organ, but fiction in general does that.
She created Steven in the same way other human beings are created. Her powers came in to play by her shapeshifting the necessary plumbing to facilitate procreation. And holding that form for months. Which makes a lot more sense after we found out she more or less spent thousands of years in a form different from her original one. Diamond shapeshifting is presumably on a whole other level.
edited 22nd May '18 7:02:15 PM by M84
Disgusted, but not surprisedIn a more recent interview Sugar described Steven as "human cells held together by Gem magic". Given that description turning Steven into a blob seems like the most likely outcome of removing his Gem.
The Crystal Caverns A bird's gotta sing.

Well if you rip that thing out of him, at the very least he'll bleed copiously. Especially now that we know it goes deeper than we thought.
And that's not even getting into the fact that part of what he is is that gem.
So he'll cease to exist in the sense that he'll die
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