The facts
What hyalite Opal actually is
The species behind hyalite Opal is opal, SiO₂·nH₂O; it forms in the amorphous system.
Colourless to green; uranyl ions cause the intense green daylight fluorescence and the green tint 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 1.40–1.46 and a specific gravity of about 1.90–2.20, with none cleavage.
Where hyalite Opal comes from
Commercial material comes from Zacatecas, Mexico, Erongo, Namibia and Valec, Czech Republic.
Different localities give different colour and different clarity, and the trade prices them differently. We state which one.
How hyalite Opal is treated
Untreated. Uranium-bearing material is mildly radioactive at trace level and fluoresces vivid green under long-wave UV, which is its principal collector appeal.
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 hyalite Opal is confused with
Watch for Green glass, Fluorite and Autunite — these are what turn up sold under this name.
The separation is rarely a matter of opinion: refractive index 1.40–1.46 and specific gravity 1.90–2.20 settle most of it in a minute, and magnification settles the rest.
What hyalite Opal is used for
The trades that buy hyalite Opal are mineral collecting, decorative objects and jewellery. 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, by the piece or by the carat.
Durability and care
Hardness 5.5–6.5; cleavage none. That combination decides what it can safely be set into.
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 hyalite Opal costs
Expect roughly $5–100/specimen; rarely cut, 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 hyalite Opal treated, and how?
Untreated. Uranium-bearing material is mildly radioactive at trace level and fluoresces vivid green under long-wave UV, which is its principal collector appeal.
Where does hyalite Opal come from?
Zacatecas, Mexico, Erongo, Namibia and Valec, Czech Republic. Origin affects price, so we name the locality rather than the country on every quote.
Is hyalite Opal hard enough to wear every day?
Yes. At 5.5–6.5 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 hyalite Opal cost?
Indicatively $5–100/specimen; rarely cut. 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 hyalite Opal confused with?
Most often Green glass, Fluorite and Autunite. A refractive index of 1.40–1.46 and a specific gravity near 1.90–2.20 separate it quickly.
What is hyalite Opal 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 hyalite opal?
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 hyalite opal