Parisite-(Nd)
Chemical formula: CaNd<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>F<sub>2</sub>
A rare mineral from the parisite group, a calcium and neodymium carbonate, forming small, hexagonal crystals of a pinkish-violet color.
Properties
- Mohs hardness
- 4.5
- Luster
- Vitreous to resinous
- Streak
- White
- Density
- 4.37
- Cleavage
- Distinct on {0001}
- Fracture
- Uneven to subconchoidal
- Transparency
- Transparent to translucent
- Crystal system
- Hexagonal
Diagnostic features
## Identification Amateur identification of parisite-(Nd) is practically impossible and requires advanced analytical methods, such as EDS or WDS spectroscopy, to confirm the dominance of neodymium over other rare-earth elements. Visually, it can be suspected based on the hexagonal crystal shape, pinkish-violet color, and co-occurrence with other rare-earth minerals in known localities. ## Distinguishing from Similar Minerals It can be confused with other minerals from the parisite group, such as parisite-(Ce) or synchysite-(Nd). Differentiation without specialized chemical analysis is impossible. From other pink minerals (e.g., rhodochrosite), it is distinguished by its crystal form and occurrence environment. ## Crystal Forms It forms small, sharply terminated, hexagonal (six-sided) crystals with a tabular or short-prismatic habit. They often occur as radial or rosette-like aggregates.
Geological environment
## Genesis Parisite-(Nd) is a hydrothermal mineral. It forms in carbonatites and in hydrothermal veins associated with alkaline igneous rocks, rich in rare-earth elements. ## Mineral Associations It co-occurs with other rare-earth carbonate minerals, such as bastnäsite-(Ce), cordylite-(Ce), huanghoite-(Ce), as well as with aegirine, riebeckite, barite, fluorite, and monazite. ## Localities The most important and type locality for parisite-(Nd) is the enormous Bayan Obo iron ore and rare-earth element deposit in Inner Mongolia, China. This is the only confirmed and well-documented locality for this mineral in the world.
Rarity
Very rare
For collectors
## Quality Criteria The quality of collector specimens of parisite-(Nd) primarily depends on the development and sharpness of the crystals and their size, although they rarely exceed a millimeter. Clear, well-formed, hexagonal crystals and aesthetic, rosette-like aggregates are highly valued. The intensity of the pinkish-violet color also enhances the specimen's attractiveness. Contrast with the host rock (matrix) is important. ## Popular Localities The only source of collector specimens is the Bayan Obo deposit in China. Specimens from this locality are the standard for this mineral.
Care and storage
## Cleaning Cleaning with compressed air is recommended solely for dust removal. Due to the small size and fragility of the crystals, mechanical cleaning, including brushes, should be avoided. Contact with water is not advisable. ## What to Avoid Parisite-(Nd) is sensitive to acids, which cause it to effervesce vigorously and decompose. Contact with any chemicals should be avoided. It should not be heated or exposed to sudden temperature changes. ## Storage Specimens should be stored under stable conditions, away from dust and moisture. The safest storage method is a sealed "micromount" box, which protects delicate crystals from mechanical damage and contamination.