Lead

Chemical formula: Pb

Native lead is a rare mineral from the native elements group, being a naturally occurring, crystalline form of lead.

## Characteristics Native lead is a natural, elemental form of lead. It occurs extremely rarely, most often as small, irregular grains, flakes, wires, or dendritic and skeletal forms. Well-formed crystals, usually in the shape of a cube or octahedron, are extremely rare and reach small sizes. Freshly exposed surfaces have a bright, silvery-white color and a strong metallic luster, but they oxidize very quickly in the air, becoming covered with a dull, gray or black layer of oxides. ## Physical Properties Native lead is very soft and malleable – it can be scratched with a fingernail and easily cut with a knife. It is also ductile and sectile. It is characterized by very high density, which makes even small specimens surprisingly heavy. It is a good conductor of electricity. It does not exhibit cleavage, and its fracture is hackly, which is typical for ductile metals. ## Colors and Varieties This mineral does not have color varieties. Its color is constant – from silvery-white on a fresh surface to dull gray after oxidation. ## History and Name The name 'ołów' (lead) comes from the Old Slavic word "olovo". As an element and metal, it has been known since antiquity. Due to its extreme rarity in native form, it does not have a formal discovery date as a mineral or a specific discoverer. For centuries, most lead was obtained from its ores, mainly galena. ## Uses Native lead has no industrial significance due to its rarity. It is solely an object of interest for collectors and scientific institutions.

Properties

Mohs hardness: 1.5
Color: Grey, but often coated with white hydrocerussite or related phases
Luster: Metallic
Streak: grey
Density: 11.37
Cleavage: none, malleable
Fracture: Hackly
Transparency: Opaque
Crystal system: Isometric

Diagnostic features

## Identification Key diagnostic features of native lead include its very high density (it is unnaturally heavy for its size), extreme softness (it can be scratched with a fingernail), silvery-white color on a fresh fracture, and rapid tarnishing in air. It leaves a gray streak on paper or porcelain. ## Distinguishing from Similar Minerals Native lead can be confused with native silver, native platinum, or antimony. Silver is slightly harder and does not tarnish to a dark gray as quickly. Platinum is much harder and heavier. Antimony is brittle, not malleable and ductile like lead. ## Crystal Forms Crystals are extremely rare, usually in the form of cubes, octahedra, or combinations thereof. Most often, it is found in granular, platy, wire-like, reticulated, and dendritic (skeletal) aggregates.

Geological environment

## Genesis Native lead is a mineral of low to medium temperature hydrothermal origin. It forms in the oxidation zones of lead ore deposits, mainly as a result of the reduction of its sulfides (galena) and sulfates (anglesite). It can also crystallize directly from hydrothermal solutions under strongly reducing conditions. It is also found in some metamorphic and sedimentary rocks. ## Mineral Associations It most often co-occurs with galena, cerussite, anglesite, calcite, barite, and other ore minerals. ## Localities Important historical and contemporary localities include: Långban in Sweden (known for well-formed crystals), Garpenberg mine in Sweden; Franklin and Sterling Hill in New Jersey, USA; the Coeur d'Alene district in Idaho, USA; as well as some occurrences in Russia and Australia (Broken Hill). In Poland, its occurrence has been noted in negligible quantities in the Świętokrzyskie Mountains and Lower Silesia.

Rarity

Very rare

For collectors

## Quality Criteria The most important criterion for the value of a native lead specimen is its form of occurrence. Well-formed, sharp, and lustrous crystals, which are extremely rare, are most highly prized. Specimens with dendritic or reticulated habits are also highly valued, especially if they are embedded in an aesthetic rock matrix. The size of the specimen and its purity (lack of impurities) also significantly increase its value. ## Popular Localities The most sought-after specimens by collectors, especially crystalline ones, come from the historic locality of Långban in Sweden. Specimens from Franklin, USA, are also classics. Currently, interesting dendritic specimens occasionally appear from the Garpenberg mine in Sweden.

Care and storage

## Cleaning Native lead specimens generally should not be cleaned to avoid removing the natural patina and damaging delicate forms. If cleaning is absolutely necessary, only a soft brush should be used to remove dust. Water and any chemical agents should be avoided. ## What to Avoid Avoid contact with moisture and chemicals, which can accelerate the oxidation process or destroy the mineral. Lead is very soft, so it should be protected from scratches, impacts, or falls. It should not be heated. Due to its toxicity, hands should be thoroughly washed after each contact with the specimen. ## Storage Native lead specimens are best stored in closed, dry containers (e.g., membrane boxes or display cases) away from other minerals that could scratch them. It is advisable to limit air access to slow down the oxidation process. It should be stored out of reach of children and pets.