Bainbridgeite-(YCe)

Chemical formula: Na₂Ba₂YCe₃+(CO₃)₆·₃H₂O

Bainbridgeite-(YCe) is a very rare, hydrated sodium, barium, yttrium, and cerium carbonate, forming small, hexagonal crystals with a vitreous luster.

## Characteristics Bainbridgeite-(YCe) is a complex, hydrated carbonate from the burbankite group, characterized by the presence of sodium, barium, and rare earth elements – yttrium and cerium. It occurs as very small, hexagonal, prismatic crystals, usually not exceeding 0.2 mm in length. The crystals are colorless to pale pink and exhibit a vitreous luster. Due to its extreme rarity and small crystal size, it is a mineral of purely scientific and collector interest. ## Physical Properties This mineral is transparent and has a white streak. Its Mohs hardness is approximately 4, and its density, calculated based on the formula and cell parameters, is 3.73 g/cm³. The crystals exhibit perfect cleavage in one direction. ## History and Name Bainbridgeite-(YCe) was first described in 2023 by Igor V. Pekov and his team. The name honors Bainbridge

Properties

Mohs hardness: 4
Luster: Vitreous
Streak: White
Density: 3.73
Cleavage: Perfect on {0001}
Fracture: Uneven
Transparency: Transparent
Crystal system: Hexagonal

Diagnostic features

## Identification Identification of Bainbridgeite-(YCe) is possible almost exclusively through advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS/WDS). In collector conditions, identification relies on the label from the type locality (Mont Saint-Hilaire) and the characteristic morphology of small, hexagonal crystals in association with other rare alkaline minerals. ## Differentiation from similar minerals It can be confused with other minerals from the burbankite group, such as burbankite or khanneshite. Differentiation requires specialized studies to determine the exact chemical composition, especially the proportions of rare earth elements. ## Crystal forms It forms elongated, prismatic crystals with a hexagonal cross-section, terminated by flat pinacoids. Crystals are usually very small, reaching up to 0.2 mm in length.

Geological environment

## Genesis Bainbridgeite-(YCe) forms in the late stages of hydrothermal processes within highly differentiated, alkaline igneous intrusions, such as nepheline syenites and associated pegmatites. It crystallizes in rock cavities and fractures. ## Mineral associations At the type locality (Mont Saint-Hilaire), it co-occurs with minerals such as microcline, aegirine, natrolite, analcime, sericite, petersenite-(Ce), and donnayite-(Y). ## Localities The only confirmed occurrence of this mineral in the world is the Poudrette quarry at Mont Saint-Hilaire, in the Montérégie region of Quebec, Canada. This is the type locality for this mineral.

Rarity

Extremely rare

For collectors

## Quality criteria As a "micromount" mineral, its value is primarily determined by the quality and development of the crystals, even if they are microscopic in size. Well-formed, sharply terminated, transparent crystals, clearly embedded in the rock matrix, are the most desirable. Association with other rare minerals from this locality is also important. ## Popular localities All known specimens of Bainbridgeite-(YCe) come from a single location – the Poudrette quarry at Mont Saint-Hilaire in Canada, which is one of the most famous mineralogical sites in the world, known for the occurrence of hundreds of rare and unique mineral species.

Care and storage

## Cleaning Due to its extreme rarity and fragility, mechanical cleaning is not recommended. If necessary, compressed air can be used to remove dust. Contact with water and chemicals should be avoided. ## What to avoid The mineral is sensitive to acids, which can damage it. Rapid temperature changes and prolonged exposure to moisture should be avoided, as it is a hydrated mineral. ## Storage Specimens should be stored under stable conditions, in sealed "micromount" containers, protecting them from dust, moisture, and mechanical damage.

Sources

IMA Mineral List (CNMNC)