A Gathering of Diamonds — Eric Wilder

When Tom Logan receives a mysterious object from his missing brother - a large uncut diamond - he drags himself from the depths of his malaise and heads north to Arkansas to investigate. Along the way he meets police officer and neo-pop poet Amber Armstrong. Together, they trace a path deep into the high Ouachitas where they discover a secret hidden for over four hundred years, and solve the mystery of Tom's brother's unexplained disapearance.