Switzerite

Chemical formula: Mn<sup>2+</sup><sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>·7H<sub>2</sub>O

Switzerite is a rare, hydrated manganese phosphate, forming characteristic, scaly aggregates of reddish-brown color and pearly luster.

## Characteristics Switzerite is a hydrated manganese phosphate, most commonly occurring as aggregates of small, scaly or bladed crystals. It forms flexible, lamellar aggregates, as well as rosetted or spherulitic forms. Its most characteristic feature is its tendency to rapidly oxidize in air, causing a color change from an initial pale-brown or pinkish hue to dark brown to almost black. ## Physical Properties Switzerite crystals are very soft, with a Mohs hardness of 2.5. They exhibit perfect cleavage in one direction, which accounts for their lamellar appearance. The luster of fresh specimens is pearly, but due to oxidation, it becomes dull or earthy. This mineral is flexible but not elastic. Its density is approximately 2.89 g/cm³. ## Colors and Varieties Freshly exposed switzerite ranges in color from pale-brown, through brownish-pink to reddish-brown. Under the influence of atmospheric oxygen, it rapidly darkens, turning dark brown, and eventually becoming almost black. No distinct color varieties or commercial varieties are recognized. ## History and Name The mineral was named in honor of George

Properties

Mohs hardness
2.5
Luster
Pearly
Streak
Pale brownish-gray
Density
2.89
Cleavage
Perfect on {010}
Fracture
Uneven
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Switzerite can be identified by its lamellar or scaly form, pearly luster on fresh cleavage surfaces, and characteristic color change from pale-brown to dark brown when exposed to air. It is very soft and flexible. It reacts with acids. ## Differentiation from Similar Minerals It can be confused with other manganese phosphates such as hureaulite or strengite, but its exceptionally low hardness, perfect cleavage, and rapid darkening in air are key distinguishing features. In its oxidized form, it may resemble manganese oxides (wad), but its genesis and co-occurrence with other phosphates in pegmatites aid in identification. ## Crystal Forms Crystals are most often tabular or bladed, forming scaly, lamellar, rosetted, or spherulitic aggregates. It rarely occurs as distinct, single crystals.

Geological environment

## Genesis Switzerite is a secondary mineral, formed in complex granitic pegmatites rich in phosphates. It forms as a result of hydrothermal alteration or weathering of primary manganese phosphates, such as triplite. It is an unstable mineral under surface conditions. ## Mineral Associations It often co-occurs with other phosphates, such as vivianite, strengite, hureaulite, rockbridgeite, as well as triplite, apatite, and manganese oxides. ## Localities The most important locality, which is also the type locality, is the Foote Lithium Co. mine in the Kings Mountain area, Cleveland County, North Carolina (USA). It is also known from several other localities worldwide, including pegmatites in Brazil and Namibia, where complex phosphate parageneses occur.

Rarity

Very rare

For collectors

## Quality Criteria The most prized specimens by collectors are those with clearly formed, unoxidized crystals exhibiting the characteristic brownish-pink color and pearly luster. Well-defined aggregates, especially rosetted ones, and contrasting associations with other minerals, e.g., vivianite, enhance their appeal. Due to its instability, specimens preserved in their pristine form are rare and sought after. ## Popular Localities Undoubtedly, the most desirable specimens come from the type locality – the Foote mine in North Carolina, USA. This is a classic locality for this mineral, from which the best known examples of switzerite originate.

Care and storage

Switzer

External references

Sources

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