The rover camera is equipped with a "spot" spectrograph which
essentially takes images in narrow spectral bands. This data
can be taken on fine spatial scales on interesting looking rocks.
The first rock which was selected for this analysis is one in
which a band of light color material (called the "stripe") runs
down the center of the rock. This is clearly visible in this
image which also shows the area
in which the multispectral spot scan occurred. These are shown
in the masthead to this page and each spectrum is color coded to
the location on the rock in which the spectra as measured.
While morphologically the stripe looks like a vein or an intrusion
of a different kind of material into the rock, the spectra shows
the reflectance properties between the stripe and the red sampled
areas are identical. This shows that the stripe is similar to
the nearby dark soil and probably represents a windblown accumulation
of said soil into a pre-existing crack.