The Crystal Heart resembles a huge, red, crystal structure. Pearl stated that it is connected to the most dangerous parts of the Temple. The central vein connected to the bottom of the Heart leads directly down into the Burning Room from Rose's Room. Due to the rhythmic beating and vein-like apparatuses, the Crystal Heart gives the Crystal Temple a sense of being alive. It is unknown why the Crystal Temple contains a heart, the effects that it has when removed, or where it draws its power from. However, it can be assumed that the Heart powers the Crystal Temple.
Steven gripped onto one of the blood vessel tubes and then slid down it while seeing into other rooms.
- The Crystal Heart connects to all known Crystal Gem rooms: Amethyst's and Pearl's rooms are connected via corridors on the main floor; the vein beneath the heart goes through Rose's Room (seen within the room in "Catch and Release") and leads directly into the Burning Room.
- When Steven slides down the central artery, the middle area is Rose's Room, hinted by the primary tune played in the episode "Rose's Room" and its overall cloudy appearance.
- Smaller, seemingly crystaline hearts that may be similar to the Crystal Heart can be seen inside the Injectors in the episode "On the Run" and subsequent appearances of Kindergartens, although the location and its technology are currently inactive.