The facts
What tektite actually is
Tektite is classified as impact glass, with the composition SiO₂ ~68–82% with Al, Fe, Mg, Ca oxides. It crystallises in the amorphous system.
Colour comes from near-opaque black-brown from iron in the glass, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.48–1.52. Specific gravity around 2.34–2.51. Cleavage: none (conchoidal fracture). Those three numbers separate it from most of what imitates it.
Where tektite comes from
Tektite is produced at Khon Kaen, Thailand (indochinites), Port Campbell, Victoria, Australia (australites), Belitung, Indonesia and Bosumtwi, Ghana.
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 tektite is treated
Untreated. Carved and re-shaped tektites are sold as natural forms; also imitated with slag glass. Australites with intact aerodynamic flanges carry a large premium and are frequently faked.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What tektite is confused with
In the trade tektite is most often mistaken for, or substituted by, Obsidian, Slag glass, Moldavite or Carved imitations.
The separation is rarely a matter of opinion: refractive index 1.48–1.52 and specific gravity 2.34–2.51 settle most of it in a minute, and magnification settles the rest.
What tektite is used for
Demand for tektite comes from mineral collecting, jewellery and decorative objects, 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, by the carat or by the piece.
Durability and care
Tektite is 5–6 on the Mohs scale, with none (conchoidal fracture) 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 tektite costs
As a guide, tektite trades around $0.50–10/g; flanged australites much higher.
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 tektite treated, and how?
Untreated. Carved and re-shaped tektites are sold as natural forms; also imitated with slag glass. Australites with intact aerodynamic flanges carry a large premium and are frequently faked.
Where does tektite come from?
Khon Kaen, Thailand (indochinites), Port Campbell, Victoria, Australia (australites), Belitung, Indonesia and Bosumtwi, Ghana. Origin affects price, so we name the locality rather than the country on every quote.
Is tektite hard enough to wear every day?
Not really. At 5–6 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 tektite cost?
Indicatively $0.50–10/g; flanged australites much higher. 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 tektite confused with?
Most often Obsidian, Slag glass, Moldavite and Carved imitations. A refractive index of 1.48–1.52 and a specific gravity near 2.34–2.51 separate it quickly.
What is tektite used for besides jewellery?
mineral collecting and decorative objects. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for tektite?
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 tektite