Laueite
Chemical formula: Mn²⁺Fe³⁺₂(PO₄)₂(OH)₂ · 8H₂O
Laueite is a rare manganese and iron phosphate mineral, typically forming small, tabular crystals with colors ranging from honey-yellow to orange-red.
Description
## Characteristics Laueite is a hydrated manganese and iron phosphate. It most commonly occurs as small, tabular crystals, often forming radial or spherulitic aggregates. Its color ranges from honey-yellow, amber, through various shades of yellow and orange, to reddish-orange. Crystals are usually small but well-formed, making them attractive to mineral collectors. ## Physical Properties This mineral has a hardness of 3 on the Mohs scale. It exhibits a vitreous luster. It is transparent to translucent, allowing for observation of its internal structure and color. The density of laueite is approximately 2.44 g/cm³. ## Colors and Varieties Laueite occurs in shades of honey-yellow, amber, yellow, dark yellow, yellow-orange, and reddish-orange. No specific commercial or color varieties are distinguished beyond the natural variability of colors. ## History and Name Laueite was discovered and described in 1954. The mineral is named after Max von Laue (1879-1960), a German physicist and Nobel laureate, known for his research on X-ray diffraction by crystals. ## Applications Laueite has no industrial applications due to its rarity and small crystal size. It is valued solely as a collector's mineral.
Diagnostic features
## Identification Laueite can be identified by its characteristic color (from honey-yellow to orange-red), vitreous luster, and typical habit of tabular crystals, often forming radial aggregates. Its hardness of 3 on the Mohs scale is also a diagnostic feature. ## Distinguishing from Similar Minerals Laueite can be confused with other manganese and iron phosphates, such as strunzite or stewartite, which often occur in similar environments. Differences in chemical composition and crystal structure are key to distinguishing them, often requiring laboratory analysis. Macroscopically, differences in crystal habit, aggregates, and color shades can be helpful. ## Crystal Forms Laueite most commonly forms small, tabular crystals. They often occur as radial or spherulitic aggregates, where individual crystals radiate from a common center.
Geological environment
## Genesis Laueite is a secondary mineral, formed in the oxidation zones of manganese phosphate deposits. It forms as a result of low-temperature hydrothermal processes, often in fissures and cavities in pegmatites, where primary manganese phosphates undergo alteration. ## Mineral Associations Laueite often co-occurs with other phosphate minerals, such as strunzite, stewartite, rockbridgeite, vivianite, as well as with quartz and manganese minerals. ## Localities Key localities for laueite include: Hühnerkobel in Bavaria (Germany), where it was first discovered, Hagendorf-Süd also in Bavaria (Germany), Boldut Mine in Cavnic (Romania), and pegmatites in Maine (USA), for example, at the Palermo Mine in North Groton.
Rarity
Rare
Collector aspects
## Quality Criteria The most prized laueite specimens are those with well-formed, distinct crystals of intense and uniform color. Crystal size, transparency, and the aesthetics of aggregates (e.g., radial clusters) are of great importance. Specimens on matrix are often more desirable. ## Popular Localities The most sought-after specimens come from classic localities such as Hühnerkobel and Hagendorf-Süd in Germany, known for their well-formed and aesthetic crystals.
Care and storage
## Cleaning Laueite is a relatively soft mineral, so it should be handled with care. For cleaning, it is best to use a soft brush and lukewarm water. The specimen can be gently rinsed under running water or briefly immersed in distilled water to remove dust and loose impurities. ## What to Avoid Avoid using aggressive chemicals, such as acids or strong detergents, which can damage the mineral's surface. High temperatures and sudden temperature changes can also be harmful. Prolonged exposure to direct sunlight can potentially affect color intensity, so it is advisable to avoid such conditions. The mineral is hydrated, so prolonged exposure to very dry environments, which could lead to dehydration, should be avoided. ## Storage Laueite is best stored in a closed display case or box, away from dust and direct light. Due to its softness, avoid contact with harder minerals that could scratch it. Ideal conditions include stable temperature and moderate humidity.