The rover's Chemistry and Mineralogy instrument, or CheMin, is analyzing the sample to determine what minerals it contains, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Thursday.
"We are crossing a significant threshold for this mission by using CheMin on its first sample," Curiosity's project scientist John Grotzinger said. "This instrument gives us a more definitive mineral-identifying method than ever before used on Mars: X-ray diffraction.
"Confidently identifying minerals is important because minerals record the environmental conditions under which they form."
The sample, about as much material as an aspirin tablet, is from the third scoop collected by Curiosity at a patch of dusty sand called "Rocknest."
A future sample will be delivered to the rover's other internal analytic instrument, the Sample Analysis at Mars investigation, which studies samples' chemistry, JPL said.
Curiosity's two-year prime mission will see it using 10 instruments to assess whether the study area has ever offered environmental conditions favorable for microbial life, scientists said.