Realgar

Realgar is a soft, orange-red mineral with a resinous lustre, made of arsenic and sulfur. It occurs in the same places as orpiment, and its name comes from an Arabic phrase meaning “powder of the mine”. Since ancient times it has been used as a red paint, a pest poison and a traditional medicine; but it contains arsenic and is toxic. Left in the light for a long time, it crumbles by itself into a yellow powder.

Arsenic ore: As a minor ore of arsenic it is extracted in China, Peru and the Philippines. Red paint: It was traded in the Roman Empire together with orpiment, and early red paint made from it is known from China, India, Central Asia and Egypt. In the Renaissance, Venetian painters and illuminators used it from the late 15th century through the 16th; the use died out by the 18th century. Fireworks: In white-flame and star compositions, and for yellow smoke in daytime fireworks.

It has a hardness of 1.5–2 on the Mohs scale. It is soft enough to scratch with a fingernail. Its specific gravity is 3.56–3.59 g/cm³.

Its best-known localities: Shimen, Hunan, China; Getchell mine, Potosi district, Nevada, USA; Jáchymov, Karlovy Vary, Czechia; Alšar (Allchar), Kavadarci, North Macedonia; Schneeberg, Saxony, Germany.

Known localities in Türkiye: Balya, Balıkesir, Türkiye.

Its colour runs from orange-red to red; its streak (powder colour) is red-orange. Orpiment, which it is usually found with, is lemon-yellow. It is very soft (hardness 1.5–2): a fingernail scratches it, a knife can cut it, and it is slightly brittle. Its lustre lies between resinous and greasy; fresh specimens are transparent. Red cinnabar (mercury sulfide) can be mistaken for realgar; cinnabar is much heavier and has a bright scarlet streak. Both are toxic.

On the “street to diamond” value ladder it sits on step 4 of nine: Fine dimension stone and ore. Realgar is sought as a collector’s specimen; its value depends on the vividness of its colour, the sharpness and size of its crystals, freedom from damage and light decay, and a famous source such as Shimen in China or Getchell in the USA. Because it is sensitive to light, well-preserved, bright specimens are scarcer and are kept in the dark. It has also been extracted as a minor ore of arsenic, but arsenic is toxic and its uses are limited.

In traditional Chinese medicine, realgar was believed to be a universal antidote against poison and to protect against disease, snakes and evil spirits; a realgar solution was sprinkled around houses. At the Dragon Boat Festival in China, adults were advised to drink yellow wine dosed with realgar powder (xionghuang wine), and children had the character 王 (“king”) drawn on the forehead or chest with realgar slurry, or wore a realgar amulet; this was believed to protect them from illness and evil. Although pure realgar dissolves poorly, the arsenic dissolved in realgar wine is high: samples have contained 70–400 mg of arsenic compounds per litre. Arsenic is a cause of bladder, skin, liver and lung cancer, and arsenic has been found in the urine of children painted with realgar slurry. Never put realgar in drinking water or wine (“gem water”, “elixirs”), in the mouth or over a flame, never breathe its dust, and never rub it on children’s skin. This section reports beliefs; it is not health information. There is no scientific evidence for these claims and no stone replaces medical treatment.

Realgar contains arsenic; it is toxic and linked to cancer. Do not lick it, put it in your mouth or eat it; never put it in water or wine to make “gem water” or an “elixir”; never use it as a medicine, a cosmetic or something painted on children’s skin. Pure realgar dissolves poorly in water, but real specimens can contain soluble arsenic compounds, and poisonings linked to swallowing realgar have been reported. Do not burn or heat it (arsenic and sulfur fumes are released), crush it to powder or sand it. Realgar left in the light for a long time crumbles into a yellow powder; do not breathe this powder or touch it with bare hands. Wash your hands after handling. Keep specimens away from children and pets, in a closed container away from light.