Chorążewiczite

Chemical formula: Pb<sup>2+</sup><sub>2</sub>Fe<sup>3+</sup>(Te<sup>6+</sup>O<sub>6</sub>)(HCO<sub>3</sub>)

Chorążewiczyt is an extremely rare secondary tellurate mineral, discovered in Poland, forming brown, platy crystals.

## Characteristics Chorążewiczyt is a mineral with a distinctive appearance, forming aggregates of small, platy or bladed crystals, reaching up to 0.2 mm in size. These crystals often arrange themselves into rosette-like forms or create nearly parallel intergrowths. Its color ranges from brown to reddish-brown, and a strong luster, described as adamantine to submetallic, is observed on the crystal surfaces. ## Physical Properties This mineral is mostly opaque, although its thin fragments can be translucent. It exhibits perfect cleavage in one direction. Its density, calculated based on chemical composition and crystal structure, is 6.70 g/cm³. The hardness of chorążewiczyt has not yet been determined. ## Colors and Varieties It is known exclusively in shades of brown and reddish-brown. No color varieties or commercial varieties have been distinguished. ## History and Name Chorążewiczyt was officially recognized as a new mineral species by the International Mineralogical Association (IMA) in 2023 (under number IMA 2023-093). Its name honors Maciej Chorążewicz (born 1986), a Polish mineral collector who found and provided the first samples of this mineral for research. The type locality, meaning the only known place of its occurrence, is Gierczyn in Lower Silesia, Poland. ## Applications Due to its extreme rarity and microscopic crystal sizes, chorążewiczyt has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of systematic minerals and microminerals.

Properties

Luster
Adamantine to Sub-Metallic
Streak
Light brown
Density
6.70
Cleavage
Perfect on {001}
Fracture
Uneven
Transparency
Translucent to Opaque
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of chorążewiczyt is impossible without advanced analytical techniques. Due to the microscopic size of the crystals and their occurrence in complex parageneses, the only reliable method of identification is chemical analysis (e.g., EDS) and X-ray diffraction analysis (PXRD). In the field or in a collection, it can only be suspected based on its origin (Gierczyn), brown color, platy habit, and co-occurrence with other minerals of the oxidation zone. ## Distinguishing from Similar Minerals It can be confused with other rare, secondary tellurates or iron and lead oxides, which can form visually similar coatings and aggregates. Reliable differentiation from minerals such as kuznetsovite or other oxyhydroxides is only possible through laboratory analysis. ## Crystal Forms Chorążewiczyt forms thin, platy or bladed crystals. Most often, they occur as radial aggregates (rosettes) or nearly parallel intergrowths, forming small aggregates on the surface of the host rock.

Geological environment

## Genesis Chorążewiczyt is a secondary mineral. It forms under specific conditions in the oxidation zone of hydrothermal quartz-cassiterite-sulfide veins. Its crystallization is a result of the weathering of primary minerals containing lead, iron, and tellurium. ## Mineral Associations This mineral occurs in direct proximity to cassiterite, quartz, and muscovite. It is also accompanied by other rare secondary minerals, such as kuznetsovite. ## Localities The only confirmed and described occurrence of chorążewiczyt in the world is its type locality: Gierczyn near Mirsk, Lwówek Śląski County, Lower Silesian Voivodeship, Poland.

Rarity

Extremely rare

For collectors

## Quality Criteria For such a rare micromineral, the main criterion of value is its mere presence on the sample and the certainty of identification. Specimens on which chorążewiczyt aggregates are richer and their forms (e.g., rosettes) are better developed and more clearly visible are more highly valued. The aesthetics of the entire specimen, including the contrast with associated minerals, is also important. ## Popular Localities Since this mineral is known only from one place in the world, all collectible specimens come from the type locality in Gierczyn, Poland. This is therefore the only and most desirable locality for this mineral.

Care and storage

## Cleaning Chorążewiczyt specimens are extremely small and fragile. They should not be cleaned mechanically or chemically. Any attempts at cleaning, even with water, can lead to damage or loss of delicate crystals. If necessary, dust can be removed very carefully using a stream of compressed air from a distance. ## What to Avoid As a mineral containing the bicarbonate group (HCO₃), it is sensitive to acids. Contact with any chemicals, acids, detergents, and ultrasonic cleaners should be strictly avoided. It should also be protected from high temperatures and sudden temperature changes. ## Storage The safest way to store it is to place the specimen in a specialized, sealed micromount box. The box should protect the specimen from dust, shocks, and moisture. Store in stable room conditions, away from direct sunlight.

Sources

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