The facts
What sylvite actually is
The species behind sylvite is halite group, KCl; it forms in the cubic system.
Colourless to milky white; red-orange when hematite inclusions are present 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 1.490 and a specific gravity of about 1.99, with perfect cubic cleavage.
Where sylvite comes from
Commercial material comes from Stassfurt, Saxony-Anhalt, Germany, Carlsbad, Eddy County, New Mexico, USA and Saskatchewan potash basin, Canada.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How sylvite is treated
Untreated. Distinguished from halite by a sharply bitter taste and slightly lower density and RI; equally water-soluble and must be kept sealed. Essentially a potash ore and a curiosity.
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 sylvite is confused with
Watch for Halite, Carnallite and Fluorite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.490 and specific gravity 1.99 settle most of it in a minute, and magnification settles the rest.
What sylvite is used for
The trades that buy sylvite are mineral collecting and heavy industry. 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 tonne.
Durability and care
Sylvite is 2 on the Mohs scale, with perfect cubic 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 sylvite costs
Expect roughly Specimens $10–$150, 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 sylvite treated, and how?
Untreated. Distinguished from halite by a sharply bitter taste and slightly lower density and RI; equally water-soluble and must be kept sealed. Essentially a potash ore and a curiosity.
Where does sylvite come from?
Stassfurt, Saxony-Anhalt, Germany, Carlsbad, Eddy County, New Mexico, USA and Saskatchewan potash basin, Canada. Origin affects price, so we name the locality rather than the country on every quote.
Is sylvite hard enough to wear every day?
Not really. At 2 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 sylvite cost?
Indicatively Specimens $10–$150. 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 sylvite confused with?
Most often Halite, Carnallite and Fluorite. A refractive index of 1.490 and a specific gravity near 1.99 separate it quickly.
Related stones
Looking for sylvite?
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 sylvite