Sea Glass behaves very much like a standard Pearl, deferring to others for decisions and expecting to receive orders as to how she should behave. Much to Steven's objections, she thinks of him as her owner. Most of Pearl's emotions manifest in Coral, so Sea Glass remains relatively apathetic to what is happening around her. She does, however, still possess a desire to please and feels at a loss when others get irritated by her self-depreciating comments. She will occasionally mimic the personalities of others, if she believes doing so will make them happy. She also has a natural curiosity and interest in adding to her knowledge base.
Sea Glass retains most all of the original Pearl's memories, with the exception of details surrounding Rose Quartz and the rebellion. She remembers who Rose is, factually, but does not remember any of their time together, Rose's personality, or what she looked like. She feels an unexplained emptiness when she shares this fact with Steven, who sympathizes with her and says they are a lot alike.
Sea Glass has an indigo tone to her body. Her face is asymmetrical, with a single eye and gemstone on her left side and her hair falling over the right (mostly featureless) side. She also possesses only one arm, which is on her right side, although her outfit has sheer sleeves draping over both shoulders. (Her outfit is otherwise identical to the original Pearl's.) She is capable of summoning a weapon, which is a long staff, resembling a blade-less version of the original Pearl's spear. She is more adapt at using her weapon to block attacks and would rather flee than battle.
Sea Glass is the first of the two pearl halves to reconstruct herself. However, as Sea Glass is only half of a gem, she cannot survive for long periods of time without being fused with someone else. She becomes the most stable when fused with Coral or another Gem half. When she attempts to fuse with a full Gem, especially one with a dominant personality like Amethyst, she starts to be absorbed by the Gem she is fused with. Of the existing Crystal Gems, Sapphire is able to fuse with Sea Glass the longest without absorbing her. This forms the fusion Corundum.