Jungite

Chemical formula: Ca₂Zn²₄Fe³⁺₈(PO₄)₉(OH)₉·₁₆H₂O

Jungite is a very rare, hydrated zinc, calcium, and iron phosphate, forming characteristic, bright yellow aggregates with low hardness.

## Characteristics Jungite is a very rare, complex, hydrated zinc, calcium, and iron phosphate. It occurs as small, bladed or tabular crystals, which most often form rosette-like or spherulitic aggregates. Its typical appearance is bright yellow, radial clusters on the surface of other minerals, especially in cavities of phosphate rocks. ## Physical Properties This mineral is extremely soft, with a Mohs hardness of only 1, meaning it can be scratched with a fingernail. It is translucent to opaque, with a luster described as pearly or dull. The calculated density is 2.843 g/cm³. It exhibits distinct cleavage in one direction. ## Colors and Varieties Jungite has a characteristic, vivid color, ranging from bright yellow to yellowish-green. No color or commercial varieties are distinguished. ## History and Name The mineral was first described in 1977. Its name honors Gerhard Jung (1926-1998), a German mineral collector from Schramberg, who first found this mineral. The type locality is the Hagendorf South pegmatite in Bavaria, Germany.

Properties

Mohs hardness: 1
Luster: Pearly
Streak: Yellow
Density: 2.843
Cleavage: {010}
Transparency: Translucent,Opaque
Crystal system: Orthorhombic

Diagnostic features

## Identification Jungite can be identified by its characteristic bright yellow color, very low hardness (1 on the Mohs scale), and typical rosette-like or spherulitic aggregates. A yellow streak is also a diagnostic feature. ## Distinguishing from Similar Minerals It can be confused with other yellow secondary phosphate minerals. It is distinguished by its extremely low hardness, aggregate form, and specific occurrence environment in phosphate pegmatites. However, accurate identification requires advanced analytical methods. ## Crystal Forms It forms very small, bladed or tabular crystals, which usually combine into radial, rosette-like, or spherulitic aggregates. Single, well-formed crystals are extremely rare.

Geological environment

## Genesis Jungite is a secondary phosphate mineral that forms in the oxidation zones of deposits containing phosphate minerals, especially in granite pegmatites rich in phosphates. It forms as a result of the alteration of earlier minerals, such as zwieselite. ## Mineral Associations It most often co-occurs with other secondary phosphate minerals, such as strengite, phosphosiderite, rockbridgeite, as well as with quartz and hematite. It occurs on the surface of these minerals or fills small fissures. ## Localities This is a very rare mineral, known from only a few localities worldwide. The most important and type locality is the Hagendorf South pegmatite in Waidhaus, Bavaria (Germany). In addition, occurrences have been reported in Spain (mine "La Paloma", Murcia) and Portugal (e.g., in Mangualde).

Rarity

Very rare

For collectors

## Quality Criteria The most prized jungite specimens are those with well-formed, distinct rosette aggregates of intense, bright yellow color. The contrast with the rock matrix and the presence of associated minerals are also important. Due to the microscopic size of the crystals, specimens are primarily evaluated based on the aesthetics of the entire cluster and its abundance on the rock surface.

Care and storage

## Cleaning Jungite specimens are extremely delicate and soft. Mechanical cleaning is not recommended. If absolutely necessary, a very careful stream of compressed air can be used to remove dust. Avoid contact with water, which can damage the mineral. ## What to Avoid Absolutely avoid contact with water, chemicals, acids, and detergents. Due to its very low hardness (1 on the Mohs scale), it is susceptible to scratches and mechanical damage from the slightest touch. Protect it from vibrations and impacts. ## Storage Jungite specimens should be stored exclusively in closed "micromount" boxes, away from other minerals that could damage them. It is not suitable for open display. It must be protected from dust and moisture.

External references

https://www.mindat.org/min-2122.html