Ammonites were cephalopods (same groups that includes the squid and octopus). They dominated the shallow warm Tethys sea but went extinct all except for the line that led to rare modern Chambered Nautilus. A bit of fosslized shell is carefully preserved in layers of crystal. No two stones are alike. Let me know if you prefer a stone with more deep blue, teal blue, green, orange or purple (or a kaleidoscopic mixutre of two or more colors) and I will select a stone for you. Bezel and and are handmade from recycled gold. You can contribute your old gold pieces to use in this ring that I will custom make for you. Pictures of stones are to give an idea of color range, I may no longer have those exact stones. Stones used in ring range from 3x5mm to 9x10mm. Matching stacking hammered bands can be ordered separately to make an unconventional wedding ring set.