In what ways does luck bring Kino and Juana bitter friends?

Luck brings Kino and Juana bitter feelings as they find a valuable pearl that initially brings hope for a better life but leads to tragedy and loss. The sudden wealth from the pearl attracts greed, envy, and violence from others, intensifying the hardships and challenges they face. Ultimately, the supposed luck of finding the pearl brings more misfortune than blessings to Kino and Juana, leading to a sense of bitterness and betrayal.