Realgar
Realgar is a sulfide mineral recognized among collectors for its crystal form and distribution, with notable Chinese occurrences.
About Realgar
Realgar belongs to the sulfide class in the realgar group and has the chemical formula As4S4. It crystallizes in the monoclinic system and is relatively soft, requiring careful handling. Its combination of structural character and global distribution make it a recognized species in both systematic and aesthetic collections.
Identification & care
Specimens usually show short prismatic, striated crystals; massive, granular, earthy coatings; compact. Its color is typically dark red to orange-red and vivid scarlet-red. The luster is resinous, greasy, adamantine, the streak is orange-yellow, and specimens range from transparent to translucent. The cleavage is good on {010}. The fracture is conchoidal to uneven, which aids identification.
Collector context
How it forms
In terms of geology, Realgar forms in low-temperature hydrothermal veins, fumarolic deposits, hot spring sinters; often associated with orpiment and stibnite. It is commonly found in association with orpiment, stibnite, cinnabar, pyrite, calcite, barite, native arsenic.
Classic Chinese localities
**Shimen deposit** is a benchmark source for realgar.
Why collectors care
Collectors pursue Realgar for the clarity of its crystal form and, in good material, saturated color that reads instantly across a display case. A well-terminated realgar on clean matrix photographs well, identifies quickly, and anchors a cabinet piece. Top Chinese specimens over the last two decades have reset the bar for what realgar looks like at collector grade.
What affects value
Value in Realgar is assessed, in typical order of weight, against: (1) locality provenance; (2) size relative to the species norm; (3) crystal form and termination sharpness; (4) color saturation and zoning; (5) transparency and internal clarity; (6) matrix quality and aesthetic balance; (7) condition (absence of damage, chips, or repair). Cleaning quality and verified locality documentation act as multipliers across the above.
Naming history
The name Realgar has a specific etymological and historical context — see Mindat's reference entry for provenance details. We have retained naming data at the record level; published prose is paraphrased from factual fields rather than copied from source.