Martian particle identified as halomonas campisalis , a species of the
halophile microbes.

A Martian soil particle examined by the atomic force microscope on
board Phoenix is identified as a  halomonas campisalis , a microbial
species of the halophile family.

Almost identical are the following Earthly and Martian halomonas
campisalis:
Fig. 1: Earthly  halomonas campisalis (SEM, at 10,000X); note the two
rods in the lower right.
       http://www.wretch.cc/album/show.php?i=lin440315&b=20&f=1555262599&p=82

Fig.2: Martian  halomonas campisalis micrograph; note the particle is
marked by red line at center:
 http://www.wretch.cc/album/show.php?i=lin440315&b=20&f=1555262601&p=83

Source of Fig. 1:
http://web.mst.edu/~mmormile/

Source of Fig. 2:
http://www.marsroverblog.com/dyn/entry/70561/discussion_page/181