Alvesite

Chemical formula: NaKZr₄+Si₆O₁₅·₂H₂O

An extremely rare sodium, potassium, and zirconium silicate, discovered in Scotland, forming colorless, microscopic crystals.

## Characteristics Alvesite is a newly discovered, very rare mineral from the silicate group, being a hydrated sodium, potassium, and zirconium silicate. It occurs as small, anhedral to subhedral grains, which form aggregates up to 0.5 mm in size. Visually, it is inconspicuous – its crystals are colorless and completely transparent. ## Physical Properties Alvesite crystals exhibit a vitreous luster. Due to the microscopic size of the specimens, hardness has not been precisely determined. The density, calculated based on the formula and unit cell parameters, is approximately 2.81 g/cm³. ## Colors and Varieties This mineral is colorless. No colored varieties or commercial forms are known. ## History and Name Alvesite was officially recognized as a new mineral by the International Mineralogical Association (IMA) in 2021 (IMA number 2021-078). Its name comes from the parish of Alves in Moray, Scotland, the area where the type material was found. ## Applications Due to its extreme rarity and microscopic size, alvesite has no practical or commercial application. It is solely of scientific interest and is an object of interest for specialized collectors of rare minerals (so-called micromounts).

Properties

Luster: Vitreous
Streak: White
Density: 2.81
Transparency: Transparent
Crystal system: Orthorhombic

Diagnostic features

## Identification Identification of alvesite is impossible without advanced analytical methods, such as Raman spectroscopy or X-ray microanalysis (EDS/WDS). In collector conditions, identification relies solely on a label from a trusted source and knowledge of associated minerals from the type locality. ## Distinguishing from Similar Minerals In the form of microscopic, colorless grains, it can be indistinguishable from many other minerals, e.g., quartz, some zeolites, or elpidite. Certain differentiation requires specialized laboratory equipment. ## Crystal Forms It forms anhedral (irregularly shaped, not developing its own faces) to subhedral (partially developed) crystals, which combine into small, granular aggregates.

Geological environment

## Genesis Alvesite forms in an alkaline pegmatite environment. The type material was found in a loose block of quartz-aegirine-arfvedsonite pegmatite. ## Mineral Associations It co-occurs with quartz, aegirine, arfvedsonite, microcline, elpidite, and minerals from the lovozerite group. ## Localities The only known occurrence in the world is the type locality near Clach-a-Choilich (Reiseter area), north of the road from Forres to Elgin, in Moray, Scotland, United Kingdom.

Rarity

Extremely rare

For collectors

## Quality Criteria For such a rare mineral, the only criterion is its confirmed presence on a fragment of the matrix rock. The size of the aggregate and the richness of its occurrence on the matrix increase the scientific and collector value of the specimen. ## Market Prices There is no established market for this mineral. Specimens may occasionally appear in the offerings of specialized rare mineral dealers, and their price depends on the quality of the specimen and the reputation of the seller. ## Popular Localities The only source of specimens is the type locality in Scotland.

Care and storage

## Cleaning Alvesite specimens are typically micromounted aggregates on matrix rock. Cleaning is not recommended and should be limited to gentle dust removal using a photographic air blower. Avoid contact with water and chemical agents. ## What to Avoid Ultrasonic cleaners, steam cleaners, acids, and all solvents should be absolutely avoided. The crystals are brittle and very small, so they should be protected from shocks, vibrations, and abrasions. ## Storage The safest form of storage is a specialized, sealed micromount box, which protects the specimen from dust and mechanical damage.

Sources

IMA Mineral List (CNMNC)