A White Stone was a symbol that an Atlantean was free from the role of tribute and would not have to enter the Labyrinth as sacrifice to the Minotaur.
The stones were drawn in front of King Minos
and Queen Pasiphae
from the mouth of a hollow bull statue. A white stone meant you were safe, a black stone
meant you were to be a tribute to the Minotaur. Jason
picked one. (The Earth Bull