'Cassandra' Septarian, Fossil, and Quartz Pendant

This large Septarian stone was mined in Siberia and contains Agatized Calcite.  Electroformed with Quartz Crystals and an Ammonite Fossil (more than 35 million years old!).   Pendant measures 2 1/2" at its widest point, and hangs 3" down.  Comes on a thin black chain with lobster clasp.  The chain measures 21" long.