The facts
What hackmanite actually is
Hackmanite is classified as sodalite, with the composition Na₈Al₆Si₆O₂₄(Cl,S)₂. It crystallises in the cubic system.
Colour comes from tenebrescence from a colour centre — an electron trapped at a chloride vacancy absorbing near 545 nm, generally attributed to a sulphur species, though several published studies dispute that sulphur is necessary, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.483–1.487 (isotropic). Specific gravity around 2.15–2.35. Cleavage: poor {110}. Those three numbers separate it from most of what imitates it.
Where hackmanite comes from
Hackmanite is produced at Koksha Valley, Badakhshan, Afghanistan, Mogok, Myanmar, Mont Saint-Hilaire, Quebec, Canada and Ilímaussaq, Greenland.
The locality is part of the description, not a footnote — two stones of the same weight from two of these places are not the same stone.
How hackmanite is treated
The photochromism runs in opposite directions by origin: Canadian and Greenland material starts pink-violet and fades in sunlight, while Afghan and Myanmar material starts creamy-white and darkens to violet-pink under UV. Heating above about 500 °C destroys tenebrescence permanently. Faceted Afghan material is commonly oil-treated for clarity — GIA found clarity enhancement in every one of eight stones tested — and rough is routinely oiled and re-oiled after recutting. Synthetic hackmanite is well established.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What hackmanite is confused with
In the trade hackmanite is most often mistaken for, or substituted by, Sodalite, Amethyst, Fluorite, Synthetic hackmanite or Purple scapolite.
The separation is rarely a matter of opinion: refractive index 1.483–1.487 (isotropic) and specific gravity 2.15–2.35 settle most of it in a minute, and magnification settles the rest.
What hackmanite is used for
Demand for hackmanite comes from mineral collecting, jewellery and decorative objects, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the specimen, by the carat or by the piece.
Durability and care
Hardness 5.5–6; cleavage poor {110}. That combination decides what it can safely be set into.
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 hackmanite costs
As a guide, hackmanite trades around $10–150/ct faceted; cabochon material far less.
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 hackmanite treated, and how?
The photochromism runs in opposite directions by origin: Canadian and Greenland material starts pink-violet and fades in sunlight, while Afghan and Myanmar material starts creamy-white and darkens to violet-pink under UV. Heating above about 500 °C destroys tenebrescence permanently. Faceted Afghan material is commonly oil-treated for clarity — GIA found clarity enhancement in every one of eight stones tested — and rough is routinely oiled and re-oiled after recutting. Synthetic hackmanite is well established.
Where does hackmanite come from?
Koksha Valley, Badakhshan, Afghanistan, Mogok, Myanmar, Mont Saint-Hilaire, Quebec, Canada and Ilímaussaq, Greenland. Origin affects price, so we name the locality rather than the country on every quote.
Is hackmanite hard enough to wear every day?
Yes. At 5.5–6 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 hackmanite cost?
Indicatively $10–150/ct faceted; cabochon material far less. 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 hackmanite confused with?
Most often Sodalite, Amethyst, Fluorite, Synthetic hackmanite and Purple scapolite. A refractive index of 1.483–1.487 (isotropic) and a specific gravity near 2.15–2.35 separate it quickly.
What is hackmanite used for besides jewellery?
mineral collecting and decorative objects. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for hackmanite?
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 hackmanite