The Dragon Tears is an item from Shadowgate 64: Trials of the Four Towersfound within the cathedral. Its main ability is to strengthen the power of whatever it touches. Some of its many uses in the game are cleansing a grave to make a spirit nicer and putting out a unnatural "purple fire" by pouring it in water to make stronger water.
"The aches and pains of your recent ordeals seem to evaporate. With renewed vigor and a fresh outlook- you feel ready to take on the world." -narration upon drinking the potion.