The facts
What anhydrite actually is
Mineralogically, anhydrite is anhydrite — CaSO₄, crystallising in the orthorhombic system.
The colour is caused by colourless to pale blue-grey and lavender; trace impurities and fine inclusions produce the Peruvian 'angelite' tone. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.570–1.614, and the specific gravity sits near 2.90–2.99; cleavage is perfect {010}, very good {100}, good {001} — three at right angles.
Where anhydrite comes from
The recognised sources are Naica, Chihuahua, Mexico, Simplon Tunnel, Valais, Switzerland, Bad Ischl and Hallstatt, Austria and Ayacucho and Huanuco, Peru (angelite).
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How anhydrite is treated
Untreated in specimens, but massive 'angelite' cabochons are often waxed. Anhydrite hydrates to gypsum in contact with water, expanding as it does so — carvings must be kept dry, and this instability is under-disclosed in the wellness trade.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What anhydrite is confused with
The usual confusions are Celestine, Gypsum, Barite and Calcite.
The separation is rarely a matter of opinion: refractive index 1.570–1.614 and specific gravity 2.90–2.99 settle most of it in a minute, and magnification settles the rest.
What anhydrite is used for
Anhydrite is bought by mineral collecting, carving and sculpture and wellness and body care — 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 specimen, by the block or by the kilo.
Durability and care
Anhydrite is 3.5 on the Mohs scale, with perfect {010}, very good {100}, good {001} — three at right angles 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 anhydrite costs
Indicative pricing for anhydrite is Angelite cabochons and tumbles $3–$30; crystallised specimens $30–$600.
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 anhydrite treated, and how?
Untreated in specimens, but massive 'angelite' cabochons are often waxed. Anhydrite hydrates to gypsum in contact with water, expanding as it does so — carvings must be kept dry, and this instability is under-disclosed in the wellness trade.
Where does anhydrite come from?
Naica, Chihuahua, Mexico, Simplon Tunnel, Valais, Switzerland, Bad Ischl and Hallstatt, Austria and Ayacucho and Huanuco, Peru (angelite). Origin affects price, so we name the locality rather than the country on every quote.
Is anhydrite hard enough to wear every day?
Not really. At 3.5 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 anhydrite cost?
Indicatively Angelite cabochons and tumbles $3–$30; crystallised specimens $30–$600. 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 anhydrite confused with?
Most often Celestine, Gypsum, Barite and Calcite. A refractive index of 1.570–1.614 and a specific gravity near 2.90–2.99 separate it quickly.
What is anhydrite used for besides jewellery?
mineral collecting, carving and sculpture and wellness and body care. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for anhydrite?
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 anhydrite