Disulfodadsonite

Chemical formula: Pb₂+₁₁Sb₃+₁₃S₂-₃₀(S₂)₂-₀.₅

A rare lead and antimony sulfosalt mineral, forming acicular crystals with a metallic luster.

## Characteristics Disulfodadsonite is a rare, complex lead and antimony sulfosalt. It occurs as very fine, acicular or hair-like crystals, which often form tangled aggregates resembling felt or wool. Individual crystals are usually too small to be observed with the naked eye. The mineral has a steel-gray to black color and a metallic luster. ## Physical Properties Crystals are flexible and pliable. Due to its microcrystalline nature, hardness and density have not been precisely measured. The luster is metallic, and the mineral is opaque. ## History and Name The mineral's name refers to its chemical composition – the presence of an additional disulfide (S₂) group in its structure – and its relationship to the structurally similar mineral, dadsonite. It was formally described as a new mineral species by E. Makovicky and S. Karup-Møller in 1996, based on material from the Izok Lake mine in Canada.

Properties

Luster: Metallic
Streak: Black
Cleavage: Good on {100}
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Disulfodadsonite is primarily recognizable by its characteristic mode of occurrence as tangled, felt-like or woolly aggregates composed of very fine, acicular crystals with a metallic luster. Identification requires advanced analytical methods, such as chemical analysis (EDS) and X-ray diffraction (XRD). ## Distinguishing from similar minerals It can be confused with other acicular sulfosalts, such as jamesonite, boulangerite, zinkenite, or dadsonite itself. Differentiation from these minerals is practically impossible without specialized laboratory equipment. Determining the chemical composition and structural parameters is key. ## Crystal forms It forms elongated, acicular or hair-like crystals, stretched along the [010] axis. These crystals almost always occur as dense, tangled or radial aggregates.

Geological environment

## Genesis It is a hydrothermal mineral. It forms in ore veins, where it crystallizes in the late stages of deposit formation, under low to medium temperature conditions. It occurs in paragenesis with other sulfides and sulfosalts. ## Mineral associations It most commonly co-occurs with quartz, galena, sphalerite, pyrite, chalcopyrite, arsenopyrite, boulangerite, and dadsonite. ## Localities The most important occurrences of this very rare mineral are the Izok Lake mine in Nunavut, Canada (type locality), and the Vurinos mine in Greece.

Rarity

Very rare

For collectors

## Quality criteria The most prized specimens are those with rich, dense, and well-preserved aggregates of acicular crystals, ideally contrasting with a light matrix, e.g., quartz. Due to its rarity, any well-documented specimen holds significant value for specialized collectors. ## Popular localities Specimens from the type locality, the Izok Lake deposit in Canada, are the most sought after for scientific and historical reasons.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to the extreme delicacy of the acicular crystals, any mechanical contact, including with water or brushes, is highly inadvisable and risks destroying the specimen. ## What to avoid Avoid contact with chemicals, ultrasound, and sudden temperature changes. The fragile aggregates are very sensitive to shocks and vibrations. ## Storage It is recommended to store specimens only in closed, padded boxes or display cases to protect them from dust, mechanical damage, and air currents that could disperse the delicate crystals.

Sources

IMA Mineral List (CNMNC)