Glass-(Nd)

Chemical formula: NaCuNd(AsO₄)₂

Glaser-(Nd) is a rare sodium, neodymium, and copper arsenate, forming tiny, blue hexagonal crystals.

## Characteristics Glaser-(Nd) is a sodium, neodymium, and copper arsenate belonging to the alluaudite group. It occurs as very small, hexagonal, tabular crystals, not exceeding 0.1 mm in size. It forms rosette-like or spherulitic aggregates. It is a transparent mineral with a light blue color and a pale blue streak. ## Physical Properties Due to the microscopic size of the crystals, most physical properties, such as hardness, density, or luster, have not been precisely determined. It is known to be a brittle mineral. ## Colors and Varieties This mineral occurs in a uniform, light blue color. No color varieties are known. ## History and Name The name "Glaser-(Nd)" honors the Russian crystallographer and mineralogist Yuri Glaser (1938-1996) from St. Petersburg. The "(Nd)" suffix in the name indicates the dominance of neodymium as a rare-earth element in its chemical composition. The mineral was approved by the IMA in 2018, and its discovery was described in 2019. The type locality is the Arsenatnaya fumarole in the Tolbachik volcanic complex on Kamchatka, Russia. ## Uses Due to its extreme rarity and microscopic size, Glaser-(Nd) has no practical or commercial applications. It is of purely scientific interest and is an object of interest for specialized collectors of micromount minerals.

Properties

Luster
Vitreous
Streak
Pale blue
Cleavage
None
Fracture
Uneven
Transparency
Transparent
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of Glaser-(Nd) is possible only through advanced analytical methods, such as energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD), due to its microscopic size and co-occurrence with many other rare arsenates. Visually, at the type locality, it is characterized by a light blue color and hexagonal crystal habit forming rosette-like aggregates. ## Distinguishing from Similar Minerals It can be confused with other blue secondary minerals found in Tolbachik fumaroles, such as ericlexmanite, which has a similar color but crystallizes in the trigonal system. Final distinction requires chemical analysis to confirm the presence and dominance of neodymium. ## Crystal Forms Glaser-(Nd) crystals are very small (up to 0.1 mm), tabular, hexagonal, and flattened parallel to the {0001} plane. They typically form radial, rosette-like, or spherulitic aggregates up to 0.3 mm in size.

Geological environment

## Genesis Glaser-(Nd) is a mineral of volcanic origin, formed by exhalation processes. It crystallizes from volcanic gases in high-temperature fumaroles (exhalations), where it deposits on rock surfaces, such as basalt. ## Mineral Associations At the type locality, on Tolbachik volcano, Glaser-(Nd) co-occurs with many other rare arsenates, such as alarsite, arseniopleite, badalovite, dmitryivanovite, ericlexmanite, erythrite, pharmacolite, hematite, johillerite, lammerite, mimetite, sphaleronatroite, svabite, tenorite, tilasite, and urusovite. ## Localities The only known worldwide occurrence of Glaser-(Nd) is its type locality – the Arsenatnaya fumarole on the second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption (1975-1976) on Kamchatka, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria As a micromineral, the main criterion for collectible value is the richness and aesthetics of crystal aggregates on the rock matrix. The most desirable specimens feature well-formed, undamaged, rosette-like clusters of intense blue color, contrasting well with the substrate. Association with other rare minerals from this locality is also important. ## Popular Localities The only source of specimens is the type locality – the Arsenatnaya fumarole on Tolbachik volcano in Kamchatka. Specimens from this location are highly prized by collectors specializing in systematic minerals and micromounts.

Care and storage

## Cleaning Specimens of this mineral are extremely small and fragile, usually permanently embedded in the rock matrix. No mechanical or chemical cleaning is recommended, as this could irreversibly damage the delicate crystals. ## What to Avoid Avoid contact with any chemicals, including water. Protect the specimen from vibrations, impacts, extreme temperatures, and direct sunlight, which can cause fading. ## Storage Microscopic specimens should be stored in specialized, sealed "micromount" boxes that protect against dust and mechanical damage. Display is only possible under a microscope.

Sources

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