Abelloemringerite

Chemical formula: Cu₂+₂Pb₂+₂Mn₃+Mn₄+₃O₁₁(OH)(H₂O)₂·H₂O

Abelloemringerite is an extremely rare, black copper, lead, and manganese oxide mineral, forming reniform or botryoidal aggregates.

## Characteristics Abelloemringerite is a complex oxide containing copper, lead, and manganese. It forms black, opaque aggregates of reniform or botryoidal habit, reaching sizes of up to several millimeters. These aggregates are composed of microscopic, tabular crystals. The mineral is characterized by a strong, metallic luster. ## Physical Properties The luster is metallic, and the streak is black. The mineral is brittle, and its fracture is uneven. Hardness on the Mohs scale has not yet been determined. The density calculated based on the formula and unit cell parameters is 5.95 g/cm³. ## Colors and Varieties The mineral occurs exclusively in black color. No colored or commercial varieties are known. ## History and Name Abelloemringerite was recognized as a new mineral species by the International Mineralogical Association (IMA) in 2022. Its name honors two Spanish mineral collectors: Miquel Abelló i Roura (b. 1960) and Joan Emringer i Podás (b. 1961), who found the type material. The type locality is the Eureka mine in Catalonia, Spain. ## Applications Due to its extreme rarity, abelloemringerite has no industrial applications. It is solely an object of scientific and collecting interest for specialized micromount mineral collectors.

Properties

Luster: Metallic
Streak: Black
Density: 5.95
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Helpful identification features include black color, metallic luster, reniform or botryoidal aggregate form, and high density. The mineral occurs in a specific geochemical environment, in association with other secondary copper, lead, and manganese minerals. Certain identification requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical microanalysis (EDS/WDS). ## Distinguishing from Similar Minerals Abelloemringerite can be confused with other black manganese oxides, such as pyrolusite, hollandite, cryptomelane, or crednerite. Distinguishing them "with the naked eye" is practically impossible. A key diagnostic feature is the simultaneous presence of copper and lead in the chemical composition, which is unusual for most manganese oxides. ## Crystal Forms The mineral does not form macroscopic, well-developed crystals. It occurs in the form of spherical, reniform, or botryoidal aggregates, which consist of very small, thin tabular crystals visible only under high magnification.

Geological environment

## Genesis Abelloemringerite is a secondary mineral, forming in the oxidation zone of polymetallic (Cu-Pb-Mn) hydrothermal veins. It crystallizes as a result of weathering and alteration of primary ore minerals under conditions of low temperatures and pressures. ## Mineral Associations At the type locality, this mineral co-occurs with crednerite, pyrolusite, and other unidentified manganese oxides. ## Localities The only confirmed occurrence of abelloemringerite in the world is its type locality – Eureka mine, Castell-estaó, La Torre de Cabdella, Pallars Jussà, Lleida, Catalonia, Spain.

Rarity

Extremely rare

For collectors

## Quality Criteria As a "micromount" type mineral, its collector value depends on the richness and aesthetics of the aggregates on the rock matrix. Specimens with well-formed, shiny reniform aggregates, without mechanical damage, are most valued. Contrast with the color of the host rock and co-occurrence with other rare minerals, such as crednerite, significantly increase the attractiveness of the specimen. ## Popular Localities The only source of specimens is the Eureka mine in Spain. Material from this locality is extremely difficult to obtain and is almost exclusively available in specialized circles.

Care and storage

## Cleaning Utmost caution is recommended. Specimens should only be dry-cleaned, using a soft brush or compressed air from a safe distance to remove dust. Any contact with water and chemical agents should be avoided. ## What to Avoid The mineral is potentially sensitive to acids and other chemicals. Ultrasonic cleaners, sudden temperature changes, and humidity should be avoided. As a hydrated oxide, it may undergo changes when heated. ## Storage Abelloemringerite specimens, typically in the form of micromounts, should be stored in sealed, closed boxes, protecting them from dust, humidity, and mechanical damage. Storage under stable room conditions is entirely sufficient.

Sources

IMA Mineral List (CNMNC)