The facts
What realgar actually is
Mineralogically, realgar is realgar — As₄S₄, crystallising in the monoclinic system.
The colour is caused by as–S charge transfer giving orange-red to scarlet with a resinous lustre. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 2.538–2.704, and the specific gravity sits near 3.56; cleavage is good {010}.
Where realgar comes from
The recognised sources are Palomo Mine, Huancavelica, Peru, Shimen and Xiangxi, Hunan, China, Baia Sprie, Romania and Getchell and Twin Creeks Mines, Nevada, USA.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How realgar is treated
Untreated, but light-sensitive in a serious way: realgar converts to yellow-orange pararealgar and crumbles to powder on light exposure over months to years, so specimens must be stored in the dark. Arsenic sulphide — toxic, never handle powder.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What realgar is confused with
The usual confusions are Cinnabar, Orpiment, Crocoite, Wulfenite and Proustite.
The separation is rarely a matter of opinion: refractive index 2.538–2.704 and specific gravity 3.56 settle most of it in a minute, and magnification settles the rest.
What realgar is used for
Realgar is bought by mineral collecting and pigments — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen or by the tonne.
Durability and care
Realgar is 1.5–2 on the Mohs scale, with good {010} 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 realgar costs
Indicative pricing for realgar is Specimens $40–$5,000; fresh transparent Peruvian crystals command premiums.
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 realgar treated, and how?
Untreated, but light-sensitive in a serious way: realgar converts to yellow-orange pararealgar and crumbles to powder on light exposure over months to years, so specimens must be stored in the dark. Arsenic sulphide — toxic, never handle powder.
Where does realgar come from?
Palomo Mine, Huancavelica, Peru, Shimen and Xiangxi, Hunan, China, Baia Sprie, Romania and Getchell and Twin Creeks Mines, Nevada, USA. Origin affects price, so we name the locality rather than the country on every quote.
Is realgar hard enough to wear every day?
Not really. At 1.5–2 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 realgar cost?
Indicatively Specimens $40–$5,000; fresh transparent Peruvian crystals command premiums. 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 realgar confused with?
Most often Cinnabar, Orpiment, Crocoite, Wulfenite and Proustite. A refractive index of 2.538–2.704 and a specific gravity near 3.56 separate it quickly.
Related stones
Looking for realgar?
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 realgar