Lévyclaudite

Chemical formula: Pb₂+₈Cu₁+₃Sn₄+₇(Bi₃+,Sb₃+)₃S₂-₂₈

Lévyclaudite is a rare lead-copper-tin sulfide with bismuth and antimony, forming tiny, metallic crystals.

## Characteristics Lévyclaudite is a complex sulfide of lead, copper, tin, bismuth, and antimony. It occurs as very small, bladed or acicular crystals, rarely exceeding 1 mm in length. It forms fibrous or radial aggregates. It is an opaque mineral with a metallic luster and a steel-gray to black color. ## Physical Properties This mineral is characterized by a metallic luster. Its Mohs hardness is approximately 2.5, making it relatively soft. The density is high, around 6.96 g/cm³. ## History and Name Lévyclaudite was first described in 1997 by Z. Johan, P. Picot, and R. Pierrot. The mineral is named in honor of two French crystallographers: Claude Lévy (born 1925) and Claude Claudel, a mining engineer who found the first samples.

Properties

Mohs hardness: 2.5
Luster: Metallic
Streak: Black
Density: 6.96
Cleavage: Perfect on {100}
Fracture: Uneven
Transparency: Opaque
Crystal system: Triclinic

Diagnostic features

## Identification Identifying lévyclaudite is extremely difficult without advanced analytical methods. Identification relies on chemical analysis (EDS/WDS) and X-ray diffraction (XRD). Visually, it is simply a "small, gray, metallic mineral." ## Distinguishing from Similar Minerals It can be confused with many other small sulfides and sulfosalts, such as stannite, cylindrite, franckeite, or other minerals from the lévyclaudite group. Definitive differentiation is only possible based on chemical composition and crystallographic data. ## Crystal Forms It forms elongated, bladed or acicular crystals, often flattened. They typically occur as tangled fibrous aggregates or small radial aggregates.

Geological environment

## Genesis Lévyclaudite is a mineral of hydrothermal origin. It forms in quartz-cassiterite veins that have undergone later mineralization processes involving lead, copper, and bismuth. ## Mineral Associations This mineral co-occurs with other sulfides and sulfosalts. In its type locality (Brioude-Massiac, France), it was found in association with cassiterite, sphalerite, pyrite, chalcopyrite, galena, native bismuth, stannite, hocartite, pyrargyrite, and owyheeite. ## Localities The only confirmed occurrence of lévyclaudite in the world is its type locality: a quartz vein in the Brioude-Massiac area in the Massif Central, France.

Rarity

Extremely rare

For collectors

## Quality Criteria As a microscopic mineral, lévyclaudite is primarily valued for the mere fact of its confirmed presence in a collection. The most highly prized specimens are those where the crystals, despite their small size, are well-formed, create rich aggregates, and are set on a contrasting matrix (e.g., quartz). Precise analytical documentation confirming identification is crucial. ## Popular Localities The only source of specimens is the type locality in France. Material from this location is extremely rare and sought after by specialized micromount collectors.

Care and storage

## Cleaning Due to its extreme rarity and delicacy, lévyclaudite specimens should not be cleaned mechanically or chemically. Any treatment can damage the tiny crystals. If dust removal is necessary, compressed air can be used from a safe distance. ## What to Avoid Avoid contact with chemicals, acids, and detergents. The mineral is sensitive to mechanical damage (scratches, impacts). It should not be heated or subjected to ultrasound. ## Storage Specimens should be stored exclusively in specialized collector boxes (micromount type), protecting them from dust, moisture, and physical damage. Store in stable temperature conditions, away from direct sunlight.

Sources

IMA Mineral List (CNMNC)