I think she can. The fact that she can't shapeshift points to her not being able to but someone on reddit made a good point: Garnett says that in order to fuse, a gem needs to convert her body into light. Then she needs to trust someone else with that light. Shapeshifting also requires converting one's body into light. But if Stevonnie is any idication, fusion is possible for one gem (or in this case, half-gem) to do all the heavy lifting on the light conversion aspect. My girlfriend pointed out that maybe her glasses are blocking her gems powers, since Homeworld has programmed peridots to feel as though fusion is wrong. They're also built to act as henchmen (I think) so Homeworld wouldn't want peridots thinking they're equal to other gems, hence the brainwashing and possible power-hindering goggles. I've also realized that of the Crystal Gems, Garnett, Amethyst, Pearl, etc. that Garnett would easily be an expert in fusion. So why would she offer to fuse with Peridot if she knew they couldn't. I understand the argument that all gems have the ability to fuse, but they also have the ability to shapeshift. Even a half-gem like Steven has mastered shapeshifting in a day. So what do you think? Can Peridot fuse?