Pushcharovskite

Chemical formula: K₀.₆Cu₂+₁₈[As₅+O₂(OH)₂]₄[As₅+O₃OH]₁₀(As₅+O₄)(OH)₉.₆·₁₈.₆H₂O

Pushcharovskite is a very rare, hydrated copper arsenate with a characteristic bright green color and fibrous appearance.

## Characteristics Pushcharovskite is a secondary mineral from the arsenate group, occurring in the oxidation zones of copper ore deposits. It forms characteristic radial or fibrous aggregates, as well as clusters of acicular or hair-like crystals. Its most recognizable feature is its intense, emerald-green or bright green color, which makes it visually attractive despite the small size of its crystals. ## Physical Properties Pushcharovskite crystals are very fine and brittle. This mineral is characterized by a vitreous luster. It is translucent. Due to its occurrence as thin needles and fibers, precise determination of hardness and density is difficult; however, its hardness is estimated to be around 3 on the Mohs scale. ## Colors and Varieties This mineral occurs in a uniform, characteristic color, from emerald-green to bright green. No color varieties or commercial varieties are distinguished. ## History and Name The mineral is named in honor of Dmitry Yurievich Pushcharovsky (born 1942), a Russian crystallographer and professor at the Faculty of Geology of Moscow State University. Pushcharovskite was approved as a new mineral by the International Mineralogical Association (IMA) in 1996. It was discovered and described based on material from the Altyn-Tyube deposit in Kazakhstan. ## Uses Pushcharovskite has no industrial applications. Its significance is purely scientific and collectible, as a very rare and aesthetic secondary mineral.

Properties

Mohs hardness: 3
Luster: Vitreous
Streak: Light green
Density: 3.45
Cleavage: Perfect on {010}
Fracture: Splintery
Transparency: Translucent
Crystal system: Monoclinic

Diagnostic features

## Identification Characteristic features of pushcharovskite include its bright green color, vitreous luster, and typical forms of occurrence as radial aggregates composed of very thin, acicular or hair-like crystals. It occurs in paragenesis with other secondary copper arsenates. ## Distinguishing from Similar Minerals It can be confused with other green, acicular copper arsenates, such as olivenite, euchroite, or geminite. Differentiation requires advanced analytical methods, such as X-ray diffraction (XRD) or chemical analysis (EDS/WDS). Geological context and associated minerals can be helpful clues. ## Crystal Forms Pushcharovskite forms very thin, elongated crystals with an acicular or hair-like habit. These crystals most often occur as radial or spherulitic aggregates, as well as tangled clusters resembling felt.

Geological environment

## Genesis Pushcharovskite is a secondary mineral, formed in the oxidation zones (gossans) of hydrothermal polymetallic deposits rich in arsenic and copper. It forms as a result of the weathering of primary copper sulfides and arsenides, such as chalcopyrite and enargite. ## Mineral Associations It co-occurs with other rare secondary minerals. In its type locality (Altyn-Tyube), it was found in association with geminite, lavendulan, arsenopyrite, chalcopyrite, quartz, dolomite, and barite. ## Localities The only confirmed and described locality of pushcharovskite in the world is its discovery site – the Altyn-Tyube (Altyntobe) gold and tellurium deposit in the Karaganda Region, Kazakhstan.

Rarity

Extremely rare

For collectors

## Quality Criteria The most highly prized specimens are those with well-formed, radial aggregates of intense, emerald-green color, contrasting with the rock matrix. Due to its extreme rarity, every well-documented specimen, even a small one, holds great value for specialized collectors of rare minerals. ## Popular Localities The only source of pushcharovskite specimens is its type locality in Kazakhstan. Material from this location is extremely difficult to acquire and appears on the collector's market sporadically.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using compressed air to remove dust. Any contact with water or other liquids is highly inadvisable due to the risk of damaging the delicate crystals. Brushes or ultrasonics should not be used. ## What to Avoid Contact with water, acids, and other chemicals must be strictly avoided. The mineral is very brittle, so it must be protected from impacts, vibrations, and abrasion. It should not be heated or exposed to prolonged strong light. ## Storage It is recommended to store specimens in sealed, stable "micromount" containers that protect against dust, moisture, and mechanical damage. Display should take place under controlled, low humidity conditions.

Sources

IMA Mineral List (CNMNC)