Anorthominasragrite

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

Anorthominasragrite is a very rare, hydrated vanadyl sulfate, forming microscopic, blue crystals and coatings.

## Characteristics Anorthominasragrite is a secondary mineral from the sulfate group, chemically a hydrated vanadyl sulfate. It occurs as very small, tabular or bladed crystals, rarely exceeding 0.2 mm in length. It also forms granular aggregates, rosette-like clusters, and thin coatings and crusts on host rocks. Its most characteristic feature is its intense blue color. ## Physical Properties Anorthominasragrite crystals exhibit a vitreous luster. Due to the small size of the crystals, many physical properties, such as hardness or density, have not been precisely determined. The mineral is transparent to translucent. ## Colors and Varieties This mineral is monochromatic and occurs in various shades of blue, from light blue to dark blue. No varieties have been distinguished. ## History and Name Anorthominasragrite was first described in 1993 by Howard T. Evans Jr. and Marvin E. Mrose. Its name refers to two facts: its belonging to the triclinic system (Greek *anorthos* - oblique) and its structural relationship with minasragrite, which is its monoclinic analogue (dimorph). The name of the parent mineral, minasragrite, comes from its discovery site in the Minas Ragra mine in Peru. ## Uses Anorthominasragrite has no industrial applications. Its significance is purely scientific and collectible, as a very rare and specific vanadium mineral.

Properties

Luster
Vitreous
Streak
Light blue
Transparency
Transparent to translucent
Crystal system
Triclinic

Diagnostic features

## Identification Anorthominasragrite is identified by its intense blue color, specific form of occurrence as fine coatings and microscopic crystals, and its geological environment. Its co-occurrence with other vanadium minerals, especially patronite, is key. ## Distinguishing from Similar Minerals This mineral can be confused with minasragrite, which has an identical chemical composition and a very similar appearance. Distinguishing these two minerals is possible almost exclusively by advanced analytical methods, such as X-ray diffraction (XRD), which allows for the determination of the crystallographic system. Visually, it is difficult to distinguish from other secondary, blue vanadium or copper sulfates. ## Crystal Forms Crystals are very small, usually tabular or bladed. They often form radial or rosette-like aggregates, as well as thin, dusty coatings and crusts.

Geological environment

## Genesis Anorthominasragrite is a secondary mineral, formed by the weathering and oxidation of vanadium sulfide deposits, mainly patronite (VS₄). It forms in the oxidation zones (iron caps) of these deposits, under low-temperature conditions and under the influence of surface waters. ## Mineral Associations This mineral most often co-occurs with the mineral from which it forms - patronite. It is also accompanied by other secondary vanadium minerals, such as minasragrite, and iron sulfides like pyrite and marcasite. ## Localities The only confirmed and classic occurrence (type locality) of anorthominasragrite in the world is the Minas Ragra mine in the Pasco department, Peru. This is the world's largest vanadium deposit, known for the occurrence of many rare minerals of this element.

Rarity

Very rare

For collectors

## Quality Criteria The collector's appeal of anorthominasragrite specimens depends primarily on the intensity and saturation of the blue color and the richness of the coating on the host rock. The most prized specimens are those where well-formed microcrystals forming rosette-like clusters are visible, even under magnification. Due to the microscopic size of the crystals, their form and purity are of secondary importance compared to the overall coverage and color. ## Popular Localities The only source of collectible specimens is the historical type locality - the Minas Ragra mine in Peru. Material from this location is extremely rare on the market.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to its water solubility and extreme delicacy, any contact with liquids and mechanical cleaning should be avoided. ## What to Avoid Contact with water must be absolutely avoided, as it can dissolve and destroy the mineral. It should also be protected from high air humidity, which can lead to its slow degradation. Avoid vibrations and shocks. ## Storage Anorthominasragrite specimens must be stored in sealed, dry containers, preferably with a desiccant (e.g., silica gel). They should be displayed away from sources of heat and moisture.

Sources

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