This amazing iridescent, multicoloured ammolite gemstone is ethically sourced and the oxidised silver is recycled.

Ammolite is fossilised ammonite shell made of aragonite (the same substance as pearl nacre). It is the same hardness as pearl.

This piece of ammolite was excavated on a small scale from the riverbank at the Bear Paw formation in Alberta, Canada by members of the Native American Blackfoot tribe, using low-impact methods and a short supply chain.

Ammolite is the remains of the shell of a prehistoric ammonite, an underwater mollusc similar to a nautilus. It’s one of the few organic-origin gemstones, along with pearl and amber. The Gemological Institute of America (GIA) explains that “unlike the vast majority of ammonite deposits found around the world, the specimens [used for production of ammolite] have a fossilized outer shell that’s iridescent as a result of replacement by aragonite.”

The chain is oxidised sterling silver and is 45cm (18”) long. The same care instructions apply to this stone as to pearl jewellery.