Braitschite-(Ce)

Chemical formula: Ca₆.₁₅Na₀.₈₅Ce³⁺₂[B₆O₇(OH)₃(O,OH)₃]₄·H₂O

A very rare calcium, sodium, and cerium borate, forming microscopic, hexagonal crystals in marine evaporites.

## Characteristics Braitschite-(Ce) is an extremely rare, hydrated borate of calcium, sodium, and rare earth elements, with cerium being dominant. It occurs as very small, hexagonal, tabular or prismatic crystals, rarely exceeding 0.3 mm. It typically forms radial aggregates or rosettes. It is a brittle mineral. ## Physical Properties Crystals exhibit a vitreous to pearly luster on cleavage surfaces. The mineral is transparent to translucent. Its Mohs hardness is approximately 5, and its density is close to 3.1 g/cm³. ## Colors and Varieties Braitschite-(Ce) is most often colorless, white, or has delicate shades of pink and red. The pink coloration is likely due to neodymium impurities. No commercial or gemological varieties are distinguished. ## History and Name The mineral was named in honor of Otto Braitsch (1921-1966), a German mineralogist and professor at the University of Freiburg, for his contributions to the study of salt deposits. The suffix -(Ce) indicates cerium as the dominant rare earth element in its composition. It was first described in 1968 based on material from the Moab salt dome, Utah, USA.

Properties

Mohs hardness: 5
Color: Colorless to white
Luster: Vitreous, Pearly
Streak: White
Density: 2.903
Cleavage: Perfect on {0001}
Fracture: Uneven
Transparency: Transparent to translucent
Crystal system: Hexagonal

Diagnostic features

## Identification Identification of Braitschite-(Ce) is extremely difficult without advanced analytical methods. Preliminary identification is based on its occurrence in a specific geological environment (marine evaporites) and its characteristic, microscopic, hexagonal crystals forming radial aggregates. It reacts with acids. ## Distinguishing from Similar Minerals It can be confused with other borates found in salt deposits, such as hilgardite or boracite. Definitive differentiation requires chemical analysis (EDS) to confirm the presence of cerium and other rare earth elements, and X-ray diffraction (XRD) to determine the crystal structure. ## Crystal Forms It forms small, hexagonal crystals with a tabular or short-prismatic habit. It is most commonly found in the form of radial aggregates and rosettes, where individual crystals radiate from a common center.

Geological environment

## Genesis Braitschite-(Ce) is an evaporitic mineral. It forms in marine salt deposits (evaporites), within the so-called gypsum-anhydrite caps, which are located above salt domes. Its presence indicates specific chemical conditions where boron and rare earth elements were concentrated during salt crystallization. ## Mineral Associations It most commonly co-occurs with minerals typical of evaporite deposits, such as anhydrite, gypsum, halite, boracite, hilgardite, and hematite. ## Localities The most important and well-documented occurrences of this mineral worldwide are the type locality in Paradox Valley, Grand County, Utah (USA), and the Königshall-Hindenburg salt dome near Göttingen in Lower Saxony (Germany).

Rarity

Very rare

For collectors

## Quality Criteria Due to its extreme rarity and microscopic crystal size, every analytically confirmed specimen is valuable to specialized collectors and scientific institutions. Samples with well-formed, even if microscopic, crystals forming aesthetic rosettes or aggregates on the host rock (most often anhydrite) are most highly prized. The intensity of the pink color may slightly enhance visual appeal.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to its sensitivity to water, no liquids, including distilled water or alcohol, should be used. ## What to Avoid Contact with water and high humidity must be strictly avoided, as the mineral is hygroscopic and may dissolve or transform into other secondary minerals. It should be protected from acids and other chemicals. ## Storage Braitschite-(Ce) specimens must be stored in sealed, airtight containers or display cases with a desiccant (e.g., silica gel). This is crucial for preserving the mineral's integrity.

External references

https://www.mindat.org/min-752.html