Zircon is a human-sized Gem with a slim figure, indigo blue skin, eyelids of a darker blue, a long slim nose, and periwinkle-blue, crescent-pointed hair that resembles a surgical hood. Her uniform consists of a pair of baby-blue pants, flats of the same blue color, a boxy, long sleeved baby-blue jacket with padded shoulders and darker blue trim along the bottom, and a pale blue cravat. She wears a monocle over her right eye, which can display multiple info screens. Her gem is located on her chest, where the knot of her tie would be. She maintains the looser style shown by Blue Diamond and her court.
As her job is being a lawyer and legal counselor to Gems on Homeworld, she holds a logical and open mindset, though she does become a bit anxious if the situation isn't in her favor. If she does figure out a foothold in a situation however, she is capable of a very sound and logical statement. In such ways, she is similar to Flint in behavior, but is less confident in some of his attempts, shown when she becomes worried on going into Blue Daimond's personal quarters in order to find evidence.
It's found out later that Zircon seems calm in some more troubling situations, as she was calm and collected when Flint spoke to her about Pink Diamond, in spite of him still being banished from Homeworld, and seeing her with him would get her into trouble.
Zircon makes her appearance when The Trial was called for the Crystal Gems, as she was placed in defense for the group after 4,000 years of service to the Blue Diamond court. She was quick to show her stress on the situation, questioning that none of them knew what the case was about, and that she didn't had time to hear what a "son" was. During the first half of the Trial, Zircon tried her best to defend the Gems, though she was too humbled at first to come up with anything too convincing. She began with stating about their ignorance to the case, which was quickly shot down. she did recollect herself and called on the chief witness (Blue Pearl), and brought her to the session for questioning, stepping her up from the prosecution. Her confidence however was shot down again when Steven explained how he killed Pink Diamond.
During the recess, she was quick to show her anger, saying how all their Gemstones are on the line because of what he said. She got more information about Steven, learning that he wasn't really Rose Quartz, and he did had prior involvement with White Diamond, before Flint arrived. She went with him and Blue Pearl to Blue Diamond's personal quarters, her at first showing great concern. She quickly showed immense admiration to Flint once he got two and two together, and once the session came back on, she aided Flint in presenting the Crystal Gems as innocent, and proving that Blue Diamond wasn't shattered, but taken away by an unknown assailant.
She was found out by Flint during his investigation in the Pink Diamond case, getting information about the current status of the Gems, and finding they were still banished despite saving Blue Diamond. She brought on the flaws in the case, pointing out how little witnesses there was at said event, finding it rather suspicious as not even her pearl was present.
She was found out by White Diamond, and brought to the White Diamond Space Station in order to keep information about this from spreading. She and the others end up rescued later on and she managed to escape.
She is shown to be able to project multiple screens around her, mainly from her monocle.