Emissivity Spectra of Sulfates, Phosphate, and Chlorides
The absorption features of sulfate (gypsum and anhydrite) and phosphate
(apatite) result from vibrations of the S-O and P-O bonds in the sulfate
and phosphate anions, respectively.
The strong ionic bonding of the chlorides inhibits independent vibration between
the individual diatomic pairs (e.g., Na and Cl) but rather requires the entire
crystal lattice to vibrate as a whole.
This figure is from Lane, M.D. and P.R. Christensen,Thermal
infrared emission spectroscopy of salt minerals predicted for Mars, Icarus, 135,
528-536, 1998.
Go to the
Oxide Page
Go back to my
Home Page