The facts
What prase Opal actually is
Prase Opal is classified as common opal, with the composition SiO₂·nH₂O with Ni. It crystallises in the amorphous system.
Colour comes from ni²⁺, the same chromophore that colours chrysoprase, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.44–1.46. Specific gravity around 1.98–2.20. Cleavage: none; conchoidal fracture. Those three numbers separate it from most of what imitates it.
Where prase Opal comes from
Prase Opal is produced at Szklary, Lower Silesia, Poland, Haneti, Dodoma, Tanzania and Marlborough, Queensland, Australia.
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 prase Opal is treated
Untreated, but like all hydrous opals it can craze if allowed to dry out quickly. It is routinely sold as chrysoprase — the two share a chromophore and a colour but not a structure, and prase opal is softer and lighter.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What prase Opal is confused with
In the trade prase Opal is most often mistaken for, or substituted by, Chrysoprase, Chrysocolla chalcedony or Variscite.
The separation is rarely a matter of opinion: refractive index 1.44–1.46 and specific gravity 1.98–2.20 settle most of it in a minute, and magnification settles the rest.
What prase Opal is used for
Demand for prase Opal comes from jewellery, mineral collecting and carving and sculpture, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the carat, by the specimen or by the block.
Durability and care
Prase Opal is 5.5–6.5 on the Mohs scale, with none; conchoidal fracture 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 prase Opal costs
As a guide, prase Opal trades around Cabochons 20–200 USD; fine Tanzanian material 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 prase Opal treated, and how?
Untreated, but like all hydrous opals it can craze if allowed to dry out quickly. It is routinely sold as chrysoprase — the two share a chromophore and a colour but not a structure, and prase opal is softer and lighter.
Where does prase Opal come from?
Szklary, Lower Silesia, Poland, Haneti, Dodoma, Tanzania and Marlborough, Queensland, Australia. Origin affects price, so we name the locality rather than the country on every quote.
Is prase 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 prase Opal cost?
Indicatively Cabochons 20–200 USD; fine Tanzanian material 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 prase Opal confused with?
Most often Chrysoprase, Chrysocolla chalcedony and Variscite. A refractive index of 1.44–1.46 and a specific gravity near 1.98–2.20 separate it quickly.
What is prase Opal used for besides jewellery?
mineral collecting and carving and sculpture. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for prase 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 prase opal