The facts
What borax actually is
The species behind borax is borax, Na₂B₄O₅(OH)₄·8H₂O; it forms in the monoclinic system.
Colourless to white or grey; effloresces to opaque white tincalconite 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 1.447–1.472 and a specific gravity of about 1.71, with perfect {100}, distinct {110} cleavage.
Where borax comes from
Commercial material comes from Boron and Searles Lake, California, USA, Tibet (historic 'tincal' trade), Salar de Uyuni region, Bolivia and Kirka, Turkey.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How borax is treated
Untreated. Dehydrates quickly in air and is water-soluble; museum specimens are kept in sealed vials. Of enormous industrial importance and negligible gem importance — included here for completeness of the borate group.
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 borax is confused with
Watch for Kernite, Ulexite, Halite and Gypsum — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.447–1.472 and specific gravity 1.71 settle most of it in a minute, and magnification settles the rest.
What borax is used for
The trades that buy borax 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
Borax is 2–2.5 on the Mohs scale, with perfect {100}, distinct {110} 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 borax 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 borax treated, and how?
Untreated. Dehydrates quickly in air and is water-soluble; museum specimens are kept in sealed vials. Of enormous industrial importance and negligible gem importance — included here for completeness of the borate group.
Where does borax come from?
Boron and Searles Lake, California, USA, Tibet (historic 'tincal' trade), Salar de Uyuni region, Bolivia and Kirka, Turkey. Origin affects price, so we name the locality rather than the country on every quote.
Is borax hard enough to wear every day?
Not really. At 2–2.5 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 borax 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 borax confused with?
Most often Kernite, Ulexite, Halite and Gypsum. A refractive index of 1.447–1.472 and a specific gravity near 1.71 separate it quickly.
Related stones
Looking for borax?
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 borax