The facts
What jasper actually is
Jasper is classified as chalcedony (opaque), with the composition SiO₂ with up to 20% foreign material. It crystallises in the trigonal system.
Colour comes from iron oxides, clay and other inclusions, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.530–1.540. Specific gravity around 2.58–2.91. Cleavage: none. Those three numbers separate it from most of what imitates it.
Where jasper comes from
Jasper is produced at Madagascar (ocean jasper), Oregon, USA, India, South Africa and Western Australia (mookaite).
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 jasper is treated
Dyeing is common. Many trade names are invented and mean nothing.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What jasper is confused with
In the trade jasper is most often mistaken for, or substituted by, Dyed jasper, Agate or Rhyolite.
The separation is rarely a matter of opinion: refractive index 1.530–1.540 and specific gravity 2.58–2.91 settle most of it in a minute, and magnification settles the rest.
What jasper is used for
Demand for jasper comes from jewellery, architecture and interiors, decorative objects and mineral collecting, 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 square metre or by the piece.
Durability and care
Hardness 6.5–7; 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 jasper costs
As a guide, jasper trades around $0.20–8/ct.
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 jasper treated, and how?
Dyeing is common. Many trade names are invented and mean nothing.
Where does jasper come from?
Madagascar (ocean jasper), Oregon, USA, India, South Africa and Western Australia (mookaite). Origin affects price, so we name the locality rather than the country on every quote.
Is jasper 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 jasper cost?
Indicatively $0.20–8/ct. 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 jasper confused with?
Most often Dyed jasper, Agate and Rhyolite. A refractive index of 1.530–1.540 and a specific gravity near 2.58–2.91 separate it quickly.
What is jasper used for besides jewellery?
architecture and interiors, decorative objects and mineral collecting. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for jasper?
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 jasper