Gem Glpyh is a language that appears in writing throughout Steven Universe in the background art, and as a minor plot point in "Monster Reunion". It is presumably one of the native languages of the Gem race.
The language is depicted in the following episodes:
- "Steven the Sword Fighter" (on the columns of Pearl's Arena),
- "Sworn to the Sword", "Steven vs. Amethyst", and "Mindful Education" (on the columns of the Ancient Sky Arena),
- "Monster Reunion" (on papers that Nephrite writes on),
- "Bismuth" (on one of the weapons in Forge),
- "Gem Heist" (on the pillars of the gate to the Zoo's Containment Area),
- "Lion 4: Alternate Ending" (on the walls of Rose's Landfill),
- "Stuck Together" (on a notification in Aquamarine's Ship),
- "Off Colors" and "Lars' Head" (on a destroyed pillar and in the Off Colors' headquarters, an abandoned Homeworld Kindergarten).
- "Your Mother and Mine" (on pillars during a flashback of the Gem War)
- "Familiar" (on a doorframe of Blue Diamond's Extraction Chamber)
- "Change Your Mind" (on Obsidian's sword)
- Steven Universe: The Movie (in the book from which White Diamond reads from)
- "Little Homeschool" (on a contract at the end of the episode)
Anything about the language's grammar, orthography, or lexicon in canon has yet to be revealed, and it has not been heard spoken. It is likely not an alternative script or substitution cipher for English, as it has more than 26 characters. Some of the characters resemble traditional (or simplified) Chinese; among those characters are: 中 (middle), 門 (door), 日 (day/sun), 目 (eye), 几 (stool/amount), 月 (month/moon), 山 (mountain), 开 (open), 王 (king), 田 (field), 丑 (ugly/clown), and 巳 (Sixth Earthly Branch/snake zodiac).
The script looks similar also with the Glagolitic script, the oldest known Slavic alphabet, used for writing Old Church Slavonic.
In "Monster Reunion", Centipeetle's script writes appears somewhat different to the previous instances of the script. The elements are written similarly to the Arabic script as opposed to the runes seen on the show. Steven mistakes these for meaningless scribbling when he first sees it, but Pearl describes it as "decently legible". It is possible this is a cursive or stylized form of the written language, or a different writing system entirely.
Unleash the Light uses a sample of the official Gem script as a font, making it a direct substitution cipher for the English alphabet, but it does not appear to match Gem language as it is used in the show. This version has entirely different characters for the capitalized and lowercase versions of the same English letters.
When directly translated from these fonts into readable text, "BLAH FHJOW NVG FKKD HFG" and "OUEIT JJOKLE" hold no meaning.
- Attack the Light's (and possibly non-canon) script also somewhat resembles the Pokémon "Unown", both resembling letters of the Roman alphabet made out of lines and circles.
- Steven Sugar is the only one who knows what the symbols on the Gem structures mean.