Nitroplumbite

Chemical formula: [Pb₂+₄(OH)₄](N₅+O₃)₄

Nitroplumbite is an extremely rare, secondary lead mineral, occurring as microscopic, colorless crystals.

## Characteristics Nitroplumbite is a very rare lead nitrate. It forms extremely small, colorless, tabular or bladed crystals, reaching up to 0.2 mm in size. They typically occur as radial or tangled aggregates. Due to the microscopic size of the crystals, its visual characteristics are difficult to observe without specialized equipment. ## Physical Properties Nitroplumbite crystals exhibit a luster described as vitreous to pearly. They are transparent and colorless. Hardness and density have not been precisely measured due to the small size of the samples. ## History and Name The mineral's name refers to its chemical composition - the presence of a nitrate group (Nitro-) and lead (-plumbite, from the Latin word *plumbum* meaning lead). It was discovered in the dumps of the Redmond mine in Haywood County, North Carolina, USA. It was described in 1996 by J.L. Jambor and co-workers.

Properties

Luster: Vitreous to Pearly
Streak: White
Cleavage: Perfect on {0001}
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification Identification of nitroplumbite is only possible using advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS), due to its microscopic size and occurrence. Visual identification in the field or in a collection is practically impossible. ## Distinguishing from similar minerals It can be confused with other secondary, colorless lead minerals, such as hydrocerussite, cerussite, or anglesite, with which it often co-occurs. Certain differentiation requires specialized laboratory tests. ## Crystal forms It forms very small, thin, tabular crystals with a hexagonal outline, often elongated and flattened. These crystals combine into radial, stellate, or haphazardly tangled aggregates.

Geological environment

## Genesis Nitroplumbite is a secondary mineral, formed in the oxidation zone of lead ore deposits. Its formation is likely associated with the reaction of lead minerals with nitrate-rich solutions, which may originate from the decomposition of organic matter (e.g., bat guano) or bacterial processes. ## Mineral associations It co-occurs with other secondary lead minerals, such as hydrocerussite, cerussite, anglesite, as well as lanarkite and pyromorphite. ## Localities The only confirmed locality (type locality) for this mineral is the dumps of the Redmond mine in Haywood County, North Carolina, USA.

Rarity

Extremely rare

For collectors

## Quality criteria As a "micromount" type mineral, its collector value depends on the richness and aesthetics of the crystal aggregates observed under a microscope. Specimens with well-formed, radial crystal groups on a contrasting rock matrix are most highly valued. The certainty of identification, confirmed by analysis, is also important. ## Popular localities The only source of specimens is the type locality - the Redmond mine in the USA. Material from this location is extremely sought after by collectors specializing in rare minerals and "micromount" specimens.

Care and storage

## Cleaning Nitroplumbite specimens are extremely delicate and small, therefore they should not be cleaned mechanically or chemically. Any attempts at cleaning risk destroying the mineral. They should be left in their untouched state. ## What to avoid The mineral is likely soluble in water and acids. Contact with any liquids, as well as changes in humidity and temperature, should be avoided. Vibrations and shocks can destroy delicate aggregates. ## Storage Nitroplumbite must be stored under stable conditions, preferably in a sealed, padded "micromount" box, protecting it from dust, moisture, and mechanical damage. Display should only take place in enclosed display cases.

Sources

IMA Mineral List (CNMNC)