Ghast Tears are Items that were added in Update 0.12.1. They are dropped by Ghasts in amounts of 0-1. They are used in the process of Brewing Potions.
The Ghast Tear is a hard-to-obtain item on Minecraft. It is dropped by the Ghast mob upon death. Ghasts are only found in The Nether. Ghast Tears are, thankfully, very common drops, though they may be lost if the Ghast is killed while flying over an inaccessible area, fire, or lava, as they will burn or be impossible to reach without great difficulty.
Ghast Tears are items that have a chance to be dropped by Ghasts when they are killed. It can be very difficult to acquire Ghast Tears due to the difficulty of killing Ghasts and because Ghasts tend to hover over lava.