Block of 3 Cleoniceras ammonites with pearly shell

This block brings together three Cleoniceras ammonites of different sizes on a single rock, dating from the Albian age. The largest reveals a partially pearlescent shell, with iridescent blue, pink, and green reflections depending on the angle of light. This nacre is composed of fine layers of aragonite superimposed with great regularity, which gives it its shifting luster.