Final answer:
In 'The Alchemist,' the black and white stones provide Santiago with guidance on his journey, helping him interpret omens and stay true to his Personal Legend.
Step-by-step explanation:
The black and white stones provide Santiago with guidance on his journey. In the context of the novel The Alchemist by Paulo Coelho, these stones are named Urim and Thummim. They were given to Santiago by Melchizedek, the King of Salem, to help him make decisions by interpreting omens. These stones do not provide financial security, knowledge of the future, or protection from danger in a direct sense; their purpose is more aligned with offering guidance and helping Santiago to stay focused on his Personal Legend—or destiny—as he seeks the treasure at the Egyptian pyramids.