Most nearby rocky exoplanets are quite unlike anything in our Solar System

Astronomers and geologists have recently concluded that most rocky planets orbiting nearby stars are more diverse and exotic than previously thought, with types of rocks not found anywhere in our Solar System.    

Densest known rocky planet: Astronomers unveil portrait of 'super-exotic super-Earth'

(PhysOrg.com) -- An international team of astronomers today revealed details of a "super-exotic" exoplanet that would make the planet Pandora in the movie Avatar pale in comparison.