Drugmanite

Chemical formula: Pb²⁺₂Fe³⁺(PO₄)(PO₃OH)(OH)₂

Drugmanite is a rare lead iron phosphate, forming small, tabular crystals with a characteristic amber-brown color.

## Characteristics Drugmanite is a very rare mineral from the phosphate group, chemically classified as a hydrated lead iron phosphate. It occurs as small, tabular or bladed crystals, rarely exceeding 1-2 mm in length. The crystals are usually transparent to translucent and are characterized by a vivid, amber-brown or reddish-brown color and a vitreous luster. ## Physical Properties This mineral has a hardness ranging from 4-5 on the Mohs scale. It has a relatively high density of approximately 5.32 g/cm³, which is typical for lead-bearing minerals. The luster is described as vitreous. ## Colors and Varieties Drugmanite occurs in shades from yellowish-brown and amber to reddish-brown. No varieties have been distinguished. ## History and Name The mineral was discovered in the Richelle mine in Visé, Belgium, and described in 1978. Its name honors Jules Drugman (1875-1950), a Belgian crystallographer and curator of mineralogical collections at Oxford University, in recognition of his contributions to the study of mineral twins. ## Uses Due to its extreme rarity and microscopic crystal size, drugmanite has no industrial applications. It is solely an object of interest for collectors specializing in rare minerals and for scientists.

Properties

Mohs hardness
5-6
Color
Pale yellow
Luster
Adamantine
Streak
white
Density
0
Cleavage
Good on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Characteristic features of drugmanite include its amber-brown color, vitreous luster, tabular crystal habit, and high density. It occurs in very small sizes, often requiring magnification for identification. Association with the type locality (Belgium) and accompanying minerals is crucial. ## Distinguishing from Similar Minerals It can be confused with other rare, brown phosphates, such as pyromorphite or corkite. It is distinguished from pyromorphite by its crystal habit (pyromorphite forms hexagonal, prismatic crystals). Definitive differentiation from corkite and other visually similar minerals requires advanced chemical (EDS) or X-ray (XRD) analyses. ## Crystal Forms It forms thin, tabular crystals with a bladed habit, often grouped into small, radial or disordered aggregates. Crystals are typically elongated in one direction.

Geological environment

## Genesis Drugmanite is a secondary mineral, forming in the oxidation zones of ore deposits. At its type locality in Belgium, it was found in cavities within weathered carbonate rocks (limestones), where it formed as a result of low-temperature hydrothermal processes. ## Mineral Associations It most commonly co-occurs with other secondary phosphate and sulfate minerals. At the type locality, it was found in association with pyromorphite, corkite, and strengite. ## Localities This is an extremely rare mineral, known practically exclusively from its discovery site – the Richelle mine, located in Visé, Liège province, Belgium. This is its only confirmed and well-documented locality worldwide.

Rarity

Extremely rare

For collectors

## Quality Criteria The most prized specimens are those with well-formed, sharp, and undamaged crystals that are clearly visible on the rock matrix. Specimens where crystals form aesthetic groups or stand out with an intense, amber color and good luster are desirable. Due to the microscopic nature of the mineral, even small but well-defined crystals are considered valuable. ## Popular Localities The only source of collector specimens is the historic type locality in Richelle, Belgium. Material from this location is very rarely available on the market.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using a soft brush to remove dust. Due to the presence of lead and potential reactivity, contact with water and any chemical agents should be avoided. ## What to Avoid Ultrasonic cleaners, steam cleaners, acids, detergents, and solvents should be strictly avoided. The mineral is sensitive to chemicals and can be damaged. It should be protected from high temperatures and scratching by harder minerals. ## Storage It is recommended to store specimens in stable conditions, in a closed display box, to protect delicate crystals from mechanical damage and dust. Due to the lead content, hands should be washed after handling the specimen.

External references

Sources

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