The facts
What andesine actually is
Andesine is classified as andesine (plagioclase feldspar), with the composition (Na,Ca)(Al,Si)₄O₈. It crystallises in the triclinic system.
Colour comes from natural material is pale yellow to champagne; red and green stones on the market owe their colour to diffused copper, which is also what a laboratory looks at when it is asked whether a colour is natural.
Refractive index 1.543–1.554. Specific gravity around 2.65–2.69. Cleavage: perfect {001}, good {010}. Those three numbers separate it from most of what imitates it.
Where andesine comes from
Andesine is produced at Bolivia (pale natural material) and Inner Mongolia, China (much-disputed 'red andesine').
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 andesine is treated
The single most notorious treatment scandal in modern coloured stones: pale Chinese and Mongolian andesine was copper-diffused to red and green and marketed as a natural Tibetan gem. Assume any saturated red or green andesine is diffused unless a major laboratory says otherwise; the treatment is detectable but requires laboratory work.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What andesine is confused with
In the trade andesine is most often mistaken for, or substituted by, Oregon sunstone, Copper-diffused andesine, Red glass or Spessartine.
The separation is rarely a matter of opinion: refractive index 1.543–1.554 and specific gravity 2.65–2.69 settle most of it in a minute, and magnification settles the rest.
What andesine is used for
Demand for andesine comes from jewellery 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 or by the specimen.
Durability and care
Hardness 6–6.5; cleavage perfect {001}, good {010}. That combination decides what it can safely be set into.
Hardness is not the whole story. Perfect cleavage means the stone can split cleanly if struck along the wrong plane, whatever its Mohs number, so a protective setting matters more here than the hardness suggests.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What andesine costs
As a guide, andesine trades around $5–50/ct; heavily discounted since the diffusion scandal.
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 andesine treated, and how?
The single most notorious treatment scandal in modern coloured stones: pale Chinese and Mongolian andesine was copper-diffused to red and green and marketed as a natural Tibetan gem. Assume any saturated red or green andesine is diffused unless a major laboratory says otherwise; the treatment is detectable but requires laboratory work.
Where does andesine come from?
Bolivia (pale natural material) and Inner Mongolia, China (much-disputed 'red andesine'). Origin affects price, so we name the locality rather than the country on every quote.
Is andesine hard enough to wear every day?
With care. It is 6–6.5 on the Mohs scale, which is hard enough, but perfect {001}, good {010} cleavage means it can split if struck at the wrong angle. Use a protective setting and avoid ultrasonic cleaning.
How much does andesine cost?
Indicatively $5–50/ct; heavily discounted since the diffusion scandal. 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 andesine confused with?
Most often Oregon sunstone, Copper-diffused andesine, Red glass and Spessartine. A refractive index of 1.543–1.554 and a specific gravity near 2.65–2.69 separate it quickly.
Related stones
Looking for andesine?
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 andesine