The facts
What iris Agate actually is
The species behind iris Agate is chalcedony (agate), SiO₂; it forms in the cryptocrystalline trigonal system.
Spectral colours are diffraction from extremely fine, regularly spaced growth bands — not pigment; they appear only in thin slices with transmitted light behind them is responsible for the colour — and the chromophore, not the name, is what decides whether a colour is stable.
On the instruments it reads a refractive index of 1.530–1.539 and a specific gravity of about 2.58–2.64, with none cleavage.
Where iris Agate comes from
Commercial material comes from Horse Mountain, Oregon, USA, Rio Grande do Sul, Brazil and Chihuahua, Mexico.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How iris Agate is treated
Untreated. The effect requires slices around a millimetre thick and a point light source directly behind; it cannot be seen in reflected light, which is why so many slices sold as iris agate disappoint.
We state the treatment on every stone, including when the honest answer is that it cannot be determined. A treatment disclosed is a fact; a treatment discovered later is a refund.
What iris Agate is confused with
Watch for Ordinary banded agate, Rainbow obsidian and Ammolite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.530–1.539 and specific gravity 2.58–2.64 settle most of it in a minute, and magnification settles the rest.
What iris Agate is used for
The trades that buy iris Agate are mineral collecting and decorative objects. They do not want the same thing, and they do not pay in the same unit.
We quote each application in the unit that trade actually buys in, by the specimen or by the piece.
Durability and care
Iris Agate is 6.5–7 on the Mohs scale, with none cleavage.
With no cleavage plane to worry about, the practical limit is abrasion rather than breakage, and it takes daily wear well.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What iris Agate costs
Expect roughly Thin slices 20–200 USD depending on how strong the diffraction is, depending on quality.
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 iris Agate treated, and how?
Untreated. The effect requires slices around a millimetre thick and a point light source directly behind; it cannot be seen in reflected light, which is why so many slices sold as iris agate disappoint.
Where does iris Agate come from?
Horse Mountain, Oregon, USA, Rio Grande do Sul, Brazil and Chihuahua, Mexico. Origin affects price, so we name the locality rather than the country on every quote.
Is iris Agate hard enough to wear every day?
Yes. At 6.5–7 on the Mohs scale with no cleavage plane, it handles daily wear well. The practical limit is gradual abrasion rather than chipping.
How much does iris Agate cost?
Indicatively Thin slices 20–200 USD depending on how strong the diffraction is. 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 iris Agate confused with?
Most often Ordinary banded agate, Rainbow obsidian and Ammolite. A refractive index of 1.530–1.539 and a specific gravity near 2.58–2.64 separate it quickly.
Related stones
Looking for iris agate?
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 iris agate