Liangjunite

Chemical formula: K<sub>2</sub>(Mo<sup>6+</sup><sub>2</sub>O<sub>5</sub>)(S<sup>6+</sup>O<sub>4</sub>)<sub>2</sub>·3H<sub>2</sub>O

An extremely rare, hydrated potassium molybdate sulfate, forming colorless, prismatic microcrystals.

## Characteristics Liangjunite is a secondary mineral from the sulfate group, chemically classified as a hydrated potassium molybdate sulfate. It occurs as very small, prismatic crystals, elongated and reaching up to 0.2 mm in length. These crystals often form radial aggregates and rosettes. It is colorless to white, which, combined with its small size, makes it difficult to observe with the naked eye. ## Physical Properties The mineral is transparent and exhibits a vitreous luster. Due to the microscopic size of its crystals and its rarity, many of its physical properties, such as hardness or density, have not yet been precisely measured. ## Colors and Varieties Liangjunite is colorless or white. No colored varieties or trade names are known. ## History and Name The mineral is named in honor of Liang-Jun Wang (born 1979), a Chinese mineral collector from Guilin, who provided the sample for research. The mineral was officially approved by the International Mineralogical Association (IMA) in 2022. The type locality and only known occurrence is the A'nyemaqen ophiolite belt in China. ## Applications Liangjunite has no industrial applications. Its significance is purely scientific and for collectors, being an object of interest mainly for micromineral specialists.

Properties

Luster
Vitreous
Streak
White
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of liangjunite is impossible based on visual characteristics alone and requires advanced analytical techniques such as X-ray diffraction (XRD) or X-ray microanalysis (EDS). Its unique chemical composition and occurrence in a specific geological environment in association with molybdenite are of key importance. ## Distinguishing from Similar Minerals It can be confused with other secondary, colorless sulfates or molybdates found in the oxidation zones of ore deposits. Certain differentiation is only possible through chemical and structural analysis. ## Crystal Forms It forms elongated, prismatic crystals, often grouped into radial aggregates or small rosettes. Individual crystals rarely exceed 0.2 mm in length.

Geological environment

## Genesis Liangjunite is a secondary mineral, formed as a result of weathering and oxidation of primary sulfide minerals, mainly molybdenite and pyrite. This process occurs under low-temperature conditions, in the presence of water and oxygen. ## Mineral Associations This mineral occurs in direct proximity to molybdenite and pyrite, which are its parent minerals. ## Localities The only confirmed worldwide occurrence is the type locality – the A'nyemaqen ophiolite belt, in Maqên County, Golog Prefecture, Qinghai Province, China.

Rarity

Extremely rare

For collectors

## Quality Criteria For micromineral collectors, the most desirable specimens are those with well-formed, sharp crystals forming aesthetic aggregates, for example, in the form of rosettes. The abundance of the mineral on the rock matrix and a clear association with molybdenite are also highly valued. ## Popular Localities The only specimens come from the type locality in Qinghai Province, China, which makes them extremely difficult to acquire.

Care and storage

## Cleaning Specimens should only be dry-cleaned, using a gentle stream of air from a photographic blower to remove dust. Avoid any contact with water and chemical agents. ## What to Avoid As a hydrated mineral, liangjunite is sensitive to high temperatures, which can lead to its dehydration and destruction of its structure. It should be protected from moisture, chemicals, and mechanical shocks due to its fragility and small size. ## Storage It is recommended to store specimens in sealed, closed "micromount" boxes, which protect against dust, physical damage, and sudden changes in ambient humidity.

Sources

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