Wenlanzhangite-(Y)

Chemical formula: Y₂V₃+₂V₄+₂(SiO₄)₂O₄(OH)₄

Wenlanzhangite-(Y) is a very rare nesosilicate mineral, distinguished by its black color and occurrence as microscopic, radial aggregates.

## Characteristics Wenlanzhangite-(Y) is an extremely rare silicate mineral from the nesosilicate group, containing yttrium and vanadium. It forms very small, radial or spherulitic aggregates, reaching up to 0.3 mm in size. Individual crystals within these aggregates are lath-like or acicular and are too small for naked-eye observation. The mineral is black and opaque, with a blackish-brown streak. ## Physical Properties Due to the microscopic size of the crystals, most physical properties have not been precisely determined. Hardness is unknown but estimated to be around 5-6 on the Mohs scale based on analogy with other silicates. The density calculated from the formula and unit cell parameters is 4.45 g/cm³. The mineral exhibits a luster described as submetallic to greasy. ## History and Name The mineral was approved by the International Mineralogical Association (IMA) in 2019 under number IMA2019-057. Its name honors Wenlan Zhang (born 1963), a Chinese mineralogist and crystallographer from the China University of Geosciences in Beijing, for his contributions to vanadium mineral research. The "-(Y)" suffix in the name indicates the dominance of yttrium in a specific site within the crystal structure, in accordance with rare-earth mineral naming conventions. ## Applications Wenlanzhangite-(Y) has no commercial or industrial applications. Its significance is purely scientific and as a collector's item, being a unique and newly discovered mineral species.

Properties

Mohs hardness: 5-6
Luster: Submetallic to greasy
Streak: Blackish-brown
Density: 4.45
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of wenlanzhangite-(Y) is possible only through advanced analytical methods, such as Raman spectroscopy, X-ray diffraction (XRD), and chemical analysis using an electron microprobe (EDS/WDS). Visually, under high magnification, characteristic black, radial aggregates can be observed on the host rock. ## Distinguishing from Similar Minerals Due to its unique chemical composition and structure, it is not easily confused with other minerals after analysis. Visually, without magnification, it may resemble other black, acicular or radial minerals, such as some tourmalines (schorl), goethite, or pyrolusite. Differentiation requires specialized laboratory equipment. ## Crystal Forms The mineral forms radial or spherulitic aggregates composed of very fine, lath-like or acicular crystals. Individual, well-formed crystals are not observed.

Geological environment

## Genesis Wenlanzhangite-(Y) forms under hydrothermal conditions within quartz veins cutting black shales. Its crystallization is associated with the mobilization and concentration of yttrium, vanadium, and silicon from surrounding organic-rich sedimentary rocks. This process occurs at relatively low temperatures. ## Mineral Associations This mineral co-occurs with quartz, karelianite, chlorelloestadite, fluorite, xenotime-(Y), zircon, monazite-(Ce), and minerals from the apatite group. ## Localities The only known occurrence of wenlanzhangite-(Y) in the world (type locality) is the Xiangyang quartz diorite quarry, located near Shiyan City in Hubei Province, China.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a wenlanzhangite-(Y) specimen is primarily assessed based on the abundance and size of the aggregates on the rock matrix. The most desirable specimens are those with numerous, well-defined, radial aggregates, clearly visible against contrasting quartz. Due to the microscopic nature of the mineral, the quality of microphotography is crucial. ## Popular Localities The only source of specimens is the type locality in Hubei Province, China. All specimens available on the collector's market originate from this single location.

Care and storage

## Cleaning Specimens of wenlanzhangite-(Y) are extremely delicate due to their microscopic size and acicular aggregate form. Cleaning is not recommended. If absolutely necessary, compressed air can be used from a safe distance to remove dust. Any mechanical contact should be avoided. ## What to Avoid Contact with water, chemicals, and especially acids, must be strictly avoided. Specimens should not be subjected to ultrasonic cleaning. The mineral is sensitive to shocks and abrasions, which can destroy the delicate crystalline aggregates. ## Storage Specimens should be stored exclusively in specialized "micromount" boxes that protect against dust, vibrations, and mechanical damage. Store in a dry place, away from direct sunlight and heat sources.

Sources

IMA Mineral List (CNMNC)