Two blue blood vessel remains beautifully preserved—one on Mars for 3
billion years, the other in Pennsylvania for 300 million years.

Someone had doubt on the above, so I checked and re-produced following
two better photos:

Fig. 1: NASA photo of “Rosy-red” Martian soil, expanded many times:
http://www.flickr.com/photos/hortonheardawho/2599111808/

Fig. 2: Beautiful blue blood vessel remains found in Specimen SK2 cut
from a Carboniferous human calvarium fossil owned by Mr. Ed Conrad of
Pennsylvania
http://www.wretch.cc/album/show.php?i=lin440315&b=19&f=1328555058&p=54