The Fifth Season, by N.K. Jemisin
Now on the Nebula shortlist (where it's second among Goodreads, third on LibraryThing) this is one of the most buzzed novels of last year. I very much enjoyed the world-building, both the existence of a minority with powers of manipulating rock and other elements, and the politics of how that works out in practice. I was less excited by the plot and characters, and lost track once or twice. If it gets onto the Hugo ballot I shall give it another try.