Lapis Lazuli is a Homeworld gem with an all blue palette. She has short, blue hair and wears a top that ties around her neck as well as a long skirt. Her clothes have two blue triangles on them resembling a diamond and she is so far the only gem to not wear footwear. Her gem is shaped like a tear drop and has no facets. She first appeared in the episode "Mirror Gem".
She was found by the Crystal Gems in the Galaxy Warp while her gem was cracked and trapped in a mirror preventing her from regenerating. Pearl tried to use the mirror Lapis was trapped in to teach Steven about gems, but it did nothing leading Pearl to believe that it was broken. Steven kept the mirror and took it around Beach City with him where Lapis revealed that she could communicate through the mirror and quickly became good friends with Steven. Wanting to introduce Lapis to the other Crystal Gems, Steven took Lapis back to the Beach House. When the Crystal Gems found out that Lapis was communicating with Steven they tried to take the mirror away and bubble it. Steven then ran away with Lapis to try and protect her from the Crystal Gems. Once they were away Lapis showed Steven how to free her from the mirror and Steven released her gem, smashing the mirror once and for all. Once the Crystal Gems had caught up to them they were aggressive towards Lapis causing her to lash out and use her hydrokinesis, temporarily pushing the Crystal Gems back. Feeling alone and homesick, Lapis left the Crystal Gems on the Beach while she disappeared into the ocean.
In the episode "Ocean Gem" Lapis Lazuli stole the ocean to construct a water tower in an attempt to get back home to Homeworld. The residents of Beach City were devastated by the consicences of the Ocean being stolen so the Crystal Gems, Greg, Lion and Connie went to find Lapis and get back the Ocean, but Lapis was determined to get home and wouldn't give it back. She created powerful water constructs to fight the Crystal Gems and tried to drown Connie and Steven. After a little convincing Lapis let Steven go to the top of the tower to speak with her and she explained that she only wanted to go home. She showed Steven that her gem was cracked so he told Lapis about his healing powers and healed it for her, allowing Lapis to summon her wings and fly back to Homeworld.