The facts
What ammolite actually is
Mineralogically, ammolite is fossil ammonite nacre — CaCO₃ (aragonite), crystallising in the orthorhombic system.
The colour is caused by interference in stacked aragonite platelets. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.52–1.68, and the specific gravity sits near 2.60–2.85; cleavage is none.
Where ammolite comes from
The recognised sources are Bearpaw Formation, Alberta, Canada — commercially unique.
That is the whole list. A single source makes supply fragile and makes any claim of a second origin worth questioning.
How ammolite is treated
Almost always stabilised and made into doublets or triplets because the layer is paper-thin.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What ammolite is confused with
The usual confusions are Doublets and triplets, Opal and Labradorite.
The separation is rarely a matter of opinion: refractive index 1.52–1.68 and specific gravity 2.60–2.85 settle most of it in a minute, and magnification settles the rest.
What ammolite is used for
Ammolite is bought by jewellery and mineral collecting — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the carat or by the specimen.
Durability and care
Ammolite is 3.5–4.5 on the Mohs scale, with none cleavage.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What ammolite costs
Indicative pricing for ammolite is $20–1,000/ct.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is ammolite treated, and how?
Almost always stabilised and made into doublets or triplets because the layer is paper-thin.
Where does ammolite come from?
Bearpaw Formation, Alberta, Canada — commercially unique. That is the only commercial source.
Is ammolite hard enough to wear every day?
Not really. At 3.5–4.5 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does ammolite cost?
Indicatively $20–1,000/ct. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is ammolite confused with?
Most often Doublets and triplets, Opal and Labradorite. A refractive index of 1.52–1.68 and a specific gravity near 2.60–2.85 separate it quickly.
Related stones
Looking for ammolite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about ammolite