This composite element concentration map of a lobster cuticle is
a landmark achievement for understanding the lobster's hard
shell. It demonstrates that the American lobster uses carbonate-
apatite (AKA bone similar to vertebrate skeletons) as a major
structural component of its cuticle. This diverges from the long
standing opinion that calcite or calcium carbonate was the major
mineral contributing to the American lobster's hard cuticle.
More The image was acquired using the Geoscience department's
Cameca SX-Ultrachron electron microprobe, which uses a highly
focused electron beam to generate characteristic X-rays. The
X-ray intensities can be mapped over the surface of a polished
section like this lobster cuticle by either moving the sample
stage, or rastering the electron beam. In this case, the image
was acquired by stage motion, and the elements displayed are
calcium (green), chlorine (red) and phosphorous (blue).