This is Sanderson's first novel, which allegedly got him his agent.

A brilliant, new fantasy world, White Sand is split into two halves: on one side are the Daysiders, and on the other the Darksiders. Daysiders have a unique ability to control and manipulate sand, bending it to their will to attack, or protect, as they wish. Darksiders have their own unique abilities and culture, and must wear thick dark lenses while on the Dayside. Generally speaking, Daysiders and Darksiders do not get along…and White Sand follows the adventures of one particular Daysider, a boy named Kenton.