Chinleite-(Y)

Chemical formula: NaY(S⁶⁺O₄)₂·H₂O

Chinleite-(Y) is a rare, colorless sodium-yttrium sulfate, forming small, hexagonal crystals with a vitreous luster.

## Characteristics Chinleite-(Y) is a hydrated sodium-yttrium sulfate. It occurs as very small, hexagonal or trigonal crystals, rarely exceeding 1 mm in length. It typically forms prismatic, elongated shapes, often terminated pyramidally. Specimens are usually colorless and transparent, with a vitreous luster. ## Physical Properties This mineral is relatively soft, with a Mohs hardness of 2.5-3, allowing it to be scratched by a copper coin. Its density is approximately 3.38 g/cm³. It is transparent and characterized by a white streak. It exhibits good cleavage in one direction. ## Colors and Varieties Chinleite-(Y) is typically colorless. No colored varieties or trade names are known. ## History and Name The mineral was first described in 1990 by Eugene E. Foord and collaborators. Its name comes from the Chinle geological formation where it was discovered, with the suffix -(Y) indicating the dominance of yttrium in its chemical composition. The type locality is the Blue Lizard mine in San Juan County, Utah, USA. ## Uses Due to its extreme rarity and microscopic crystal sizes, chinleite-(Y) has no industrial applications. It is of scientific interest only and is sought after by specialized collectors of rare minerals.

Properties

Mohs hardness: 2.5-3
Luster: Vitreous
Streak: White
Density: 3.385
Cleavage: Good parallel to [001], probably {100}
Fracture: Splintery
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification Field identification of chinleite-(Y) is practically impossible due to the microscopic size of its crystals. Identification requires advanced laboratory methods, such as chemical composition analysis (EDS) and X-ray diffraction (XRD). In a collection, it can be recognized by its characteristic hexagonal crystal form and confirmed locality. ## Distinguishing from Similar Minerals It can be confused with other microscopic sulfates or secondary minerals. Differentiation from gypsum or celestine is possible based on crystal form (hexagonal in chinleite) and hardness. However, definitive distinction requires specialized analysis. ## Crystal Forms It forms small, prismatic crystals with a hexagonal cross-section, often elongated along the crystallographic c-axis. Crystals may be terminated by trigonal pyramid faces.

Geological environment

## Genesis Chinleite-(Y) is a secondary mineral, forming in the oxidation zones of uranium-vanadium deposits. It forms as a result of weathering processes of primary minerals in sedimentary sandstone rocks, such as the Chinle Formation in the USA. ## Mineral Associations At the type locality, it co-occurs with gypsum, quartz, pyrite, montroseite, and other rare secondary uranium and vanadium minerals. ## Localities The only confirmed and thoroughly described occurrence of chinleite-(Y) is its type locality – the Blue Lizard mine in Red Canyon, San Juan County, Utah, USA.

Rarity

Very rare

For collectors

## Quality Criteria The most valuable specimens are those with well-formed, sharp, and transparent crystals, even if they are microscopic in size. It is important that the crystals are embedded on a contrasting rock matrix and undamaged. Due to its rarity, any well-documented specimen from the type locality is valuable. ## Popular Localities The only source of collectible specimens is the Blue Lizard mine in Utah, USA. Specimens from this location are highly sought after by collectors specializing in rare minerals and "micromounts."

Care and storage

## Cleaning Specimens should be cleaned with utmost care, using compressed air to remove dust. Due to the softness and small size of the crystals, contact with water and any mechanical cleaning, including brushes, should be avoided. ## What to Avoid Avoid contact with water, chemicals, and sudden temperature changes. The mineral is very brittle and soft, so it should be protected from any impacts and scratches. ## Storage It is recommended to store specimens in tightly sealed, padded "micromount" boxes to protect them from mechanical damage, dust, and moisture. Display should only occur under stable conditions.

External references

https://www.mindat.org/min-47890.html