Chinleite-(Nd)

Chemical formula: NaNd(S<sup>6+</sup>O<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O

Chinleite-(Nd) is an extremely rare sodium neodymium sulfate, forming microscopic, hexagonal crystals of a violet color.

## Characteristics Chinleite-(Nd) is a hydrated sodium neodymium sulfate. It occurs as extremely small, hexagonal, tabular crystals, rarely exceeding 0.2 mm in size. It also forms rosette-like aggregates. It is a secondary mineral, found within fossilized wood in sediments of the Chinle Formation. ## Physical Properties Due to the microscopic size of the crystals, most physical properties, such as hardness or density, have not been precisely measured. Luster is described as vitreous to pearly on cleavage surfaces. The mineral is transparent. ## Colors and Varieties It is characterized by a pale violet to violet-pink color. It has no known varieties. ## History and Name The mineral was approved by the IMA in 2018 (IMA2018-058). Its name refers to the Chinle geological formation in Arizona (USA), where it was discovered in the Blue Lizard uranium mine. The -(Nd) suffix in the name indicates the dominant rare earth element - neodymium.

Properties

Luster
Vitreous to Pearly
Streak
White
Cleavage
Perfect on {0001}
Fracture
Micaceous
Transparency
Transparent
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of Chinleite-(Nd) is possible only through advanced analytical methods, such as Raman spectroscopy, X-ray diffraction (XRD), or chemical analysis (EDS/WDS). In collector conditions, identification relies on a label from a reliable source and association with the type locality. ## Distinguishing from Similar Minerals It can be confused with other microscopic rare earth sulfates. Differentiation requires specialized chemical analysis to confirm the dominance of neodymium. ## Crystal Forms It forms very small, hexagonal, tabular crystals, often gathered in rosette-like or radial aggregates.

Geological environment

## Genesis Chinleite-(Nd) is a secondary mineral. It forms as a result of weathering processes of primary minerals containing rare earth elements in a sulfate-rich environment. At the type locality, it was found in voids in fossilized wood (araucarioxylon) within mudstones of the Chinle Formation, associated with uranium deposits. ## Mineral Associations It co-occurs with other rare sulfates, such as chinleite-(Y), as well as gypsum, jarosite, and uranium minerals. ## Localities The only confirmed and described locality in the world is the Blue Lizard Mine in San Juan County, Utah, USA.

Rarity

Extremely rare

For collectors

## Quality Criteria As a "micromount" type mineral, the value of a specimen is primarily determined by the quality and abundance of crystals visible under a microscope. The most desirable are well-formed, sharp, tabular crystals with a distinct violet color, forming aesthetic aggregates on a contrasting matrix. Confirmation of identification by a reputable laboratory is also crucial. ## Popular Localities All collector material comes from a single location - the Blue Lizard Mine in Utah, USA, which is the type locality for this mineral.

Care and storage

## Cleaning Due to its extreme rarity and fragility, specimens with this mineral (usually microscopic crystals on matrix) should not be cleaned mechanically or chemically. Contact with water, which can dissolve the mineral, should be avoided. ## What to Avoid All chemicals, ultrasonics, temperature changes, and moisture should be strictly avoided. The mineral is water-soluble. It should be protected from direct sunlight, although its effect is not fully understood. ## Storage Specimens should be stored under stable conditions, preferably in closed, padded "micromount" boxes, to protect them from physical damage, dust, and moisture.

Sources

Read more