Ghast tears are a unique item found in the game Minecraft. They are dropped by ghasts, which are large, floating mobs that inhabit the Nether dimension. When a ghast is defeated, it has a chance to drop these tears, which are a translucent, glowing substance. In the game, ghast tears are primarily used to brew potions. Specifically, they are an essential ingredient for creating Potion of Regeneration, which helps players recover health over time. Additionally, they can be used to craft Ender Crystals, which are necessary for respawning the Ender Dragon.