No one disputes that these globules were formed from stuff melted and thrown into the air by the impact, because their chemical composition matches rock from the crater itself.

ECONOMIST: Some new ideas about why life on Earth has periodic crises

Although APXS and ChemCam will tell you which chemical elements are present, they don't tell you how precisely those atoms are arranged into the crystalline structures that make up the rock, and both this mineralogy and the chemical composition are ideally needed to assign a rock name.

BBC: Cosmic coincidence on the road to Glenelg

Since cosmic radiation alters surface composition, Curiosity can drill into rock to extract pristine material from below.

CNN: Curiosity opening Martian frontier?

As well as using the rover's X-ray spectrometer on Whitewater Lake and Kirkwood to determine the chemical elements present, and thus get a better idea of their mineralogical composition, the team needs to work out the order and position of the rock layers to tell them something of their relative ages.

BBC: Nasa's 'Oppy' rover could be rolling on Martian clays