The facts
What serendibite actually is
The species behind serendibite is serendibite, Ca₂(Mg,Al)₆(Si,Al,B)₆O₂₀; it forms in the triclinic system.
Not firmly established — depth of blue tracks iron content and the mechanism is generally attributed to Fe and Fe–Ti interactions, but no species-specific spectroscopic study was found 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 1.696–1.706 in gem material; the species range runs to 1.743 and a specific gravity of about 3.42–3.52, with good {010} and {001} per the Handbook of Mineralogy, though some databases say none cleavage.
Where serendibite comes from
Commercial material comes from Gangapitiya, Kurunegala District, Sri Lanka (type locality), Mogok Valley, Myanmar, Handeni district, Tanzania and Ihosy, Madagascar.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How serendibite is treated
Untreated. Among the rarest faceted gems in existence — for years only a handful of cut stones were known, all from Sri Lanka, before Mogok material appeared. Most is near-black; transparent blue stones of a carat or more are extraordinary. Always buy with a laboratory report.
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 serendibite is confused with
Watch for Sapphire, Spinel, Black tourmaline, Iolite and Dumortierite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.696–1.706 in gem material; the species range runs to 1.743 and specific gravity 3.42–3.52 settle most of it in a minute, and magnification settles the rest.
What serendibite is used for
The trades that buy serendibite are 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 specimen.
Durability and care
Serendibite is 6.5–7 on the Mohs scale, with good {010} and {001} per the Handbook of Mineralogy, though some databases say none cleavage.
With no cleavage plane to worry about, the practical limit is abrasion rather than breakage, and it takes daily wear well.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What serendibite costs
Expect roughly $1,000–15,000/ct; translucent material far less, 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 serendibite treated, and how?
Untreated. Among the rarest faceted gems in existence — for years only a handful of cut stones were known, all from Sri Lanka, before Mogok material appeared. Most is near-black; transparent blue stones of a carat or more are extraordinary. Always buy with a laboratory report.
Where does serendibite come from?
Gangapitiya, Kurunegala District, Sri Lanka (type locality), Mogok Valley, Myanmar, Handeni district, Tanzania and Ihosy, Madagascar. Origin affects price, so we name the locality rather than the country on every quote.
Is serendibite hard enough to wear every day?
Yes. At 6.5–7 on the Mohs scale with no cleavage plane, it handles daily wear well. The practical limit is gradual abrasion rather than chipping.
How much does serendibite cost?
Indicatively $1,000–15,000/ct; translucent material far less. 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 serendibite confused with?
Most often Sapphire, Spinel, Black tourmaline, Iolite and Dumortierite. A refractive index of 1.696–1.706 in gem material; the species range runs to 1.743 and a specific gravity near 3.42–3.52 separate it quickly.
Related stones
Looking for serendibite?
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 serendibite