Books in the The Green Bone Saga, 1 series

"Jade is the lifeblood of the island of Kekon. It has been mined, traded, stolen, and killed for--and for centuries, honorable Green Bone warriors like the Kaul family have used it to enhance their magical abilities and defend the island from foreign invasion. Now the war is over and a new generation of Kauls vies for control of Kekon's bustling capital city. They care about nothing but protecting their own, cornering the jade market, and defending the districts under their protection. Ancient tradition has little place in this rapidly changing nation"--Amazon.com.