Jurassic Russian Ammonite
Phylum Mollusca; Class Cephalopoda; Subclass Ammonoidea;
Time: Jurassic, Callovian Stage
large, beautiful ammonite is Kosmoceras coming from near Ulyanovsk,
Russia. It exhibites opal iridescence of different colors that change
with angle of view, a consequence of light passing through the various
layers of aragonite and conchiolin deposited by the ammonite in life.
The lack of acidity in the depositional environment allowed them to
be preserved as you see it here. Jewel-quality material such as this
coming from Alberta, Canada is termed “Ammolite” in the
trade, and typically commands a high price. This is a stunning example
of an enherent beauty often seen when ammonites were preserved in
just the right environment.
ammonite picture to enlarge