The facts
What adularia actually is
The species behind adularia is feldspar group (alkali), KAlSi₃O₈; it forms in the monoclinic system.
Colourless; adularescence comes from light scattering off submicroscopic orthoclase–albite exsolution layers 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 1.518–1.536 and a specific gravity of about 2.54–2.61, with perfect basal, good prismatic cleavage.
Where adularia comes from
Commercial material comes from Adula Alps, Grisons, Switzerland, Val Cristallina, Ticino, Switzerland and Rakwana, Sri Lanka.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How adularia is treated
Untreated. Thin cabochons are sometimes backed with dark cement to strengthen the blue sheen, which should be disclosed and rarely is.
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 adularia is confused with
Watch for Moonstone, Sanidine and Chalcedony — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.518–1.536 and specific gravity 2.54–2.61 settle most of it in a minute, and magnification settles the rest.
What adularia is used for
The trades that buy adularia are jewellery and mineral collecting. 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 carat or by the specimen.
Durability and care
Hardness 6–6.5; cleavage perfect basal, good prismatic. That combination decides what it can safely be set into.
Hardness is not the whole story. Perfect cleavage means the stone can split cleanly if struck along the wrong plane, whatever its Mohs number, so a protective setting matters more here than the hardness suggests.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What adularia costs
Expect roughly Alpine crystals 20–300 USD per specimen; sheen cabochons 5–60 USD, 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 adularia treated, and how?
Untreated. Thin cabochons are sometimes backed with dark cement to strengthen the blue sheen, which should be disclosed and rarely is.
Where does adularia come from?
Adula Alps, Grisons, Switzerland, Val Cristallina, Ticino, Switzerland and Rakwana, Sri Lanka. Origin affects price, so we name the locality rather than the country on every quote.
Is adularia hard enough to wear every day?
With care. It is 6–6.5 on the Mohs scale, which is hard enough, but perfect basal, good prismatic cleavage means it can split if struck at the wrong angle. Use a protective setting and avoid ultrasonic cleaning.
How much does adularia cost?
Indicatively Alpine crystals 20–300 USD per specimen; sheen cabochons 5–60 USD. 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 adularia confused with?
Most often Moonstone, Sanidine and Chalcedony. A refractive index of 1.518–1.536 and a specific gravity near 2.54–2.61 separate it quickly.
Related stones
Looking for adularia?
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 adularia