What Is Ammolite?

Ammolite is one of the world's rarest gemstones, known for its brilliant iridescent colours and unique fossil origin. Unlike most gemstones, which form deep within the Earth through geological processes, Ammolite comes from the fossilized shells of ancient marine animals that lived more than 70 million years ago.

Its vibrant flashes of red, green, blue, purple, and gold have earned it recognition as one of the most visually distinctive gemstones in the world. No two pieces display colour in exactly the same way, making every gemstone completely unique.

A Gemstone Born from Fossils

Ammolite originates from the shells of ammonites, extinct marine cephalopods that once inhabited the ancient inland seas covering much of North America during the Late Cretaceous Period.

These animals were distant relatives of modern nautiluses, squid, and octopuses. After death, their shells settled onto the seafloor where, under very specific conditions, portions of the shell were preserved rather than destroyed.

Over millions of years, these preserved shell layers fossilized while retaining their original aragonite structure. It is this preserved aragonite that ultimately becomes Ammolite.

What Creates the Colours?

Unlike many gemstones, Ammolite's colours are not produced by pigments or trace minerals.

Instead, its colours result from the way light interacts with microscopic layers of aragonite within the fossil shell. As light reflects from these layers, certain wavelengths are amplified while others are cancelled out, producing the brilliant iridescent colours known as play-of-colour.

The thickness of these layers determines which colours appear. Reds and greens are most common, while blues and purples are significantly rarer.

Because the angle of light affects the colours that are visible, Ammolite often appears to shift and change as it is moved.

Found Almost Exclusively in Southern Alberta

Although ammonite fossils occur around the world, gem-quality Ammolite is found almost exclusively within the Bearpaw Formation of Southern Alberta, Canada.

The geological conditions responsible for preserving gemstone-quality shell material occurred in only a small region, making Ammolite one of the few gemstones associated almost entirely with a single location on Earth.

This geographic exclusivity is one of the reasons Ammolite is considered so rare.

A Gemstone Unlike Any Other

Ammolite occupies a unique position among gemstones. It is simultaneously a gemstone, a fossil, and a piece of natural history.

Every stone began as a living creature that inhabited an ancient sea more than 70 million years ago. Through an extraordinary combination of biology, geology, and time, those fossil shells became one of the world's most remarkable gemstones.

For collectors, jewelry enthusiasts, and fossil lovers alike, Ammolite offers something few other gemstones can: a direct connection to an ancient world preserved in colour.