Supposedly it's a piece of plastic from the rover. Not sure why your source made the huge leap and said it was metallic because NASA only initially said it was 'bright' and hadn't done any kind of chemical analysis
Sometimes it's best to look what was actually said...
Sometimes it's best to look what was actually said...
Quote:Checking a Bright Object on the Ground
"Curiosity's first scooping activity appeared to go well on Oct. 7. Subsequently, the rover team decided to refrain from using the rover's robotic arm on Oct. 8 due to the detection of a bright object on the ground that might be a piece from the rover. Instead of arm activities during the 62nd Martian day, or sol, of the mission, Curiosity is acquiring additional imaging of the object to aid the team in identifying the object and assessing possible impact, if any, to sampling activities.
Sol 62, in Mars local mean solar time at Gale Crater, will end at 12:23 a.m. Oct. 9, PDT (3:23 a.m., EDT)"
Quote:Object Likely Benign Plastic from Curiosity Rover
"Curiosity's main activity in the 62nd sol of the mission (Oct. 8, 2012) was to image a small, bright object on the ground using the Remote Micro-Imager of the Chemistry and Camera (ChemCam) instrument.
The rover team's assessment is that the bright object is something from the rover, not Martian material. It appears to be a shred of plastic material, likely benign, but it has not been definitively identified.
To proceed cautiously, the team is continuing the investigation for another day before deciding whether to resume processing of the sample in the scoop. Plans include imaging of surroundings with the Mastcam.
A sample of sand and dust scooped up on Sol 61 remains in the scoop. Plans to transfer it from the scoop into other chambers of the sample-processing device were postponed as a precaution during planning for Sol 62 after the small, bright object was detected in an image from the Mast Camera (Mastcam).
A Sol 62 raw image from ChemCam, at http://1.usa.gov/R1fZHt, shows the object in question just to left of center of the image.
Sol 62, in Mars local mean solar time at Gale Crater, will end at 12:23 a.m. Oct. 9, PDT (3:23 a.m., EDT)."