The facts
What kernite actually is
Kernite is classified as kernite, with the composition Na₂B₄O₆(OH)₂·3H₂O. It crystallises in the monoclinic system.
Colour comes from colourless to white; becomes chalky as it alters to tincalconite on exposure, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.454–1.488. Specific gravity around 1.90–1.93. Cleavage: perfect {100} and {001}. Those three numbers separate it from most of what imitates it.
Where kernite comes from
Kernite is produced at Boron (Kramer district), Kern County, California, USA, Tincalayu, Salta, Argentina and Kirka, Eskişehir, Turkey.
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 kernite is treated
Untreated but unstable: kernite dehydrates in dry air to a white tincalconite crust, so clear specimens must be sealed. Very low density and two perfect cleavages; faceted material is a laboratory curiosity.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What kernite is confused with
In the trade kernite is most often mistaken for, or substituted by, Borax, Ulexite, Colemanite or Gypsum.
The separation is rarely a matter of opinion: refractive index 1.454–1.488 and specific gravity 1.90–1.93 settle most of it in a minute, and magnification settles the rest.
What kernite is used for
Demand for kernite comes from mineral collecting and heavy industry, 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 or by the tonne.
Durability and care
Kernite is 2.5 on the Mohs scale, with perfect {100} and {001} 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 kernite costs
As a guide, kernite trades around Specimens $20–$400.
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 kernite treated, and how?
Untreated but unstable: kernite dehydrates in dry air to a white tincalconite crust, so clear specimens must be sealed. Very low density and two perfect cleavages; faceted material is a laboratory curiosity.
Where does kernite come from?
Boron (Kramer district), Kern County, California, USA, Tincalayu, Salta, Argentina and Kirka, Eskişehir, Turkey. Origin affects price, so we name the locality rather than the country on every quote.
Is kernite hard enough to wear every day?
Not really. At 2.5 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 kernite cost?
Indicatively Specimens $20–$400. 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 kernite confused with?
Most often Borax, Ulexite, Colemanite and Gypsum. A refractive index of 1.454–1.488 and a specific gravity near 1.90–1.93 separate it quickly.
Related stones
Looking for kernite?
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 kernite