Ammolite: The Rainbow Fossil from the Age of Dinosaurs

Ammolite: When a Fossil Becomes a Gemstone

Ammolite is one of the rarest gemstone materials on Earth — and also one of the most visually dramatic. Technically an opalized ammonite fossil, ammolite forms when the aragonite shell of an extinct cephalopod, buried in sediment for 65 to 75 million years, undergoes silicification and compression that transforms it into gem-quality iridescent material. The result is a stone that displays full spectral color — reds, greens, blues, and golds — shifting with every angle of light.

What Is an Ammonite?

Ammonites were free-swimming marine predators that went extinct at the end of the Cretaceous period — the same extinction event that ended the dinosaurs. They're recognizable by their spiral shell, which grew outward in a logarithmic Fibonacci pattern. Found on every continent, ammonite fossils are among the most abundant and visually striking fossils available to collectors. Our ammonite pairs and single specimens come from Madagascar and are presented as polished, exhibition-quality fossils.

Ammolite vs. Ammonite

These terms are easy to confuse. Ammonite is the fossil — the physical shell of the creature. Ammolite is the gemstone material — the specific iridescent form found primarily in the Bearpaw Formation of Alberta, Canada. We carry both: whole ammonite fossils for collectors, and ammolite specimens that showcase the opalized color play. The "edge of spiral" specimens we carry are particularly striking — a cross-section through the outer whorls of the shell, where the color play is most intense.

Adding Ammolite to Your Collection

Ammolite is a finite resource — it occurs in a geographically limited zone in Alberta and cannot be synthesized. Supply is naturally constrained. For collectors, that makes quality ammolite a sound acquisition. For anyone who simply wants something extraordinary on their shelf, a piece of ammolite is one of the few objects in the world that does something genuinely different every time you look at it.

Stone, sourced. Art, original. — Kyanite King Minerals