Plumboselite

Chemical formula: Pb<sup>2+</sup><sub>3</sub>O<sub>2</sub>(Se<sup>4+</sup>O<sub>3</sub>)

Plumboselite is a rare lead selenite, forming microscopic, tabular crystals of intense red color and adamantine luster.

## Characteristics Plumboselite is a lead oxyselenite, occurring as very small, tabular or bladed crystals, rarely exceeding 0.2 mm in length. It usually forms small aggregates or occurs as single, scattered crystals. Its most characteristic features are its intense, red to orange-red color and strong, almost adamantine luster. ## Physical properties The crystals are flexible and can be bent. The Mohs hardness is low, approximately 2. The luster is strongly resinous to adamantine. The mineral is transparent to translucent. Due to its lead content, its density is high, at 7.75 g/cm³. ## Colors and varieties Plumboselite occurs in shades from red and orange-red to reddish-orange. No varieties have been distinguished. ## History and name The mineral's name refers to its chemical composition – the presence of lead (Latin: *plumbum*) and selenium (*selenium*). It was approved as a new mineral by the IMA in 2010 (IMA2010-051), and its description was published in 2012. It was discovered on the dumps of the former uranium mine in Kletno in the Śnieżnik Massif (Poland). ## Uses Plumboselite has no industrial applications. It is solely an object of interest for collectors specializing in rare minerals or minerals from Poland.

Properties

Mohs hardness
2
Luster
Resinous to adamantine
Streak
Orange-red
Density
7.75
Cleavage
Perfect on {001}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Plumboselite is recognizable by its intense red color, strong luster, form of small, tabular crystals, and co-occurrence with other secondary selenium and lead minerals. Due to its microscopic size, identification requires the use of a stereomicroscope. ## Distinguishing from similar minerals It can be confused with other red, secondary lead minerals, such as minium, crocoite, or wulfenite. It differs from them by its crystal habit (thin tablets), paragenesis (co-occurrence with selenites), and, if in doubt, by chemical analysis (EDS), which will show the presence of selenium. ## Crystal forms It forms very thin, tabular crystals with hexagonal or octagonal outlines, as well as bladed crystals. It occurs as single crystals or small, loose aggregates.

Geological environment

## Genesis Plumboselite is a secondary mineral, forming in the oxidation (weathering) zone of polymetallic ore deposits containing selenium and lead. It forms as a result of the reaction of selenium-rich solutions with lead minerals. ## Mineral associations At the type locality (Kletno, Poland), it co-occurs with anglesite, cerussite, mimetite, wulfenite, karkonoszyte-(Ce), fluorite, quartz, hematite, and goethite. ## Localities The only confirmed locality of plumboselite in the world is the dumps of the former uranium mine "Kopaliny" in Kletno, in the Śnieżnik Massif, in the Polish Sudetes.

Rarity

Extremely rare

For collectors

## Quality criteria The quality of plumboselite specimens is assessed based on the size and development of the crystals, their number, and the aesthetic composition on the rock matrix. The most valued specimens are those with well-formed, undamaged crystals of intense red color, forming rich aggregates. Due to its extreme rarity, any well-identified specimen is valuable. ## Popular localities The only source of specimens is its type locality – Kletno in Poland. Material from this location is highly sought after by collectors specializing in systematic minerals and "micromounts."

Care and storage

## Cleaning Specimens should be cleaned very carefully, using compressed air to remove dust. Due to the extreme rarity and small size of the crystals, any mechanical and chemical contact should be avoided. ## What to avoid Avoid contact with water, acids, and any chemical agents. The crystals are very soft and brittle, susceptible to scratches and mechanical damage. They should not be subjected to ultrasound. ## Storage Plumboselite specimens should be stored in stable conditions, in closed, padded "micromount" boxes, to protect them from dust, mechanical damage, and sudden changes in humidity.

Sources

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