Manganbabingtonite

Chemical formula: Ca₂Mn₂+Fe₃+Si₅O₁₄(OH)

Manganbabingtonite is a rare calcium, manganese, and iron silicate mineral, characterized by its dark green to black color and vitreous luster.

## Characteristics Manganbabingtonite is a silicate mineral with a complex chemical composition, containing calcium, manganese, and iron. Typical specimens appear as dark green to black, often tabular or prismatic crystals. The crystal surfaces exhibit a vitreous luster, giving them a distinctive appearance. This mineral usually forms small, well-formed crystals that can occur individually or in aggregates. ## Physical Properties The Mohs hardness of manganbabingtonite ranges from 6.5 to 7, making it a relatively hard mineral. It has perfect cleavage in one direction ({001}), less perfect in another ({010}), and poor in a third ({100}). The specific gravity of this mineral is approximately 3.452 g/cm³. It is transparent to opaque. ## Colors and Varieties Manganbabingtonite occurs in colors ranging from dark green to black, often with a yellowish-green tint. No specific commercial or color varieties are widely recognized. ## History and Name The name manganbabingtonite is derived from its chemical composition, indicating the presence of manganese, and from babingtonite, with which it is isostructural. Babingtonite was named after the British physician and mineralogist William Babington (1756-1833). Manganbabingtonite was described as a distinct mineral species due to the dominance of manganese over iron in its structure. ## Uses Manganbabingtonite has no industrial applications due to its rarity and lack of specific properties that would make it useful in industry. It is solely a collector's mineral, prized by enthusiasts of rare silicates.

Properties

Mohs hardness: 6.5-7
Luster: Szklisty
Streak: Biała
Density: 3.452
Cleavage: Perfect on {001}, less perfect on {010}, poor on {100}
Fracture: Nierówny
Transparency: Translucent,Opaque
Crystal system: Triclinic

Diagnostic features

## Identification Manganbabingtonite can be identified by its dark green to black color, vitreous luster, and characteristic, often tabular or prismatic crystals. Its Mohs hardness (6.5-7) is also a diagnostic feature. For precise identification, laboratory analyses, such as chemical composition analysis, are often necessary. ## Distinguishing from Similar Minerals Manganbabingtonite can be confused with babingtonite, which has a similar appearance and structure but differs in the dominant element in its composition (iron in babingtonite, manganese in manganbabingtonite). From other dark silicates, such as amphiboles or pyroxenes, it is distinguished by its specific cleavage and crystallographic system. ## Crystal Forms Manganbabingtonite forms triclinic crystals, often tabular or short prismatic. Crystals are usually well-formed, with distinct faces. It can also occur as fine-grained aggregates.

Geological environment

## Genesis Manganbabingtonite is a secondary mineral that forms in hydrothermal environments, often in altered metamorphic rocks or in pegmatite veins. It also occurs in fractures and cavities in igneous rocks, where it crystallizes from solutions rich in silicon, calcium, manganese, and iron. ## Mineral Associations Manganbabingtonite often co-occurs with other silicate minerals, such as quartz, epidote, calcite, as well as with manganese and iron minerals. It can be found in association with babingtonite, zeolites, and prehnite. ## Localities Known localities of manganbabingtonite include areas in Japan, such as Ehime Prefecture, where it was first described. It also occurs in other locations worldwide, although these are usually rare and small occurrences.

Rarity

Very Rare

For collectors

## Quality Criteria The most prized manganbabingtonite specimens are those with well-formed, large, and aesthetic crystals of intense, dark green to black color. Transparency and a distinct vitreous luster also increase the attractiveness of the specimen. Specimens with a matrix on which the crystals are well-displayed are also highly valued. ## Popular Localities The most sought-after specimens come from Japan, especially from its type locality. Other localities, though less known, can also provide interesting specimens for collectors.

Care and storage

## Cleaning Manganbabingtonite specimens can be cleaned using a soft brush and lukewarm water. For heavier dirt, a mild soap solution can be used, followed by thorough rinsing with clean water. It is important to dry the specimen thoroughly after cleaning to avoid deposits. ## What to Avoid Avoid using aggressive chemicals, such as acids or strong detergents, which can damage the mineral's surface. Prolonged exposure to direct sunlight may potentially affect the color, although this is not a commonly reported problem for this mineral. Also avoid sudden temperature changes, which can lead to cracking. ## Storage Manganbabingtonite is best stored in enclosed display cases or boxes, away from dust and humidity. Due to its hardness, it can be stored with other minerals of similar hardness, but individual protection of more valuable specimens is always recommended to prevent scratches.

External references

https://www.mindat.org/min-2494.html