Schindlerite

Chemical formula: (N³⁻H₄)₄Na₂[V⁵⁺₁₀O₂₈]·10H₂O

Schindlerite is an extremely rare, water-soluble sodium-ammonium decavanadate, forming microscopic, orange crystals.

## Characteristics Schindlerite is a hydrated sodium-ammonium decavanadate, occurring as extremely small, platy or bladed crystals, rarely exceeding 0.2 mm in length. It forms radial aggregates and crusts. It is a secondary mineral, forming under specific conditions on mine dumps. Due to its water solubility, it is unstable in humid environments. ## Physical Properties Schindlerite crystals are very brittle. The mineral exhibits a vitreous luster and is transparent to translucent. Its hardness and density have not been precisely measured due to the small size and rarity of the crystals. ## Colors and Varieties Schindlerite occurs in a characteristic, bright orange color. No color varieties or commercial varieties are known. ## History and Name The mineral was named after Michael Schindler (born 1967), a professor of geology at Laurentian University in Sudbury (Canada), for his contributions to the mineralogy and crystal chemistry of vanadates. It was approved by the International Mineralogical Association (IMA) in 2021 (IMA2021-061). It was discovered on the dumps of the St. Jude uranium and vanadium mine in San Miguel County, Colorado, USA. ## Uses Schindlerite has no industrial applications. It is solely an object of scientific and collecting interest for specialized micromineral collectors.

Properties

Mohs hardness
2
Color
Orange
Luster
Vitreous
Streak
Yellow
Density
2.461
Cleavage
{010}
Fracture
Brittle
Transparency
Transparent
Crystal system
Triclinic

Diagnostic features

## Identification Schindlerite can be identified by its bright orange color, characteristic small, platy crystals forming radial aggregates, and its occurrence in association with other secondary vanadates. A key diagnostic feature is its water solubility. ## Distinguishing from Similar Minerals It can be confused with other orange, secondary vanadium minerals, such as pascoite or huemulite, which are also water-soluble. Definitive differentiation requires advanced analytical methods, such as X-ray diffraction (XRD) or chemical analysis (EDS), due to the presence of sodium and ammonium groups in the schindlerite structure. ## Crystal Forms Crystals are very small, usually platy or bladed, flattened parallel to {010}. They often form fan-shaped or radial aggregates and thin crusts on the host rock.

Geological environment

## Genesis Schindlerite is a secondary mineral that crystallizes under low-temperature conditions as a result of the weathering of primary vanadium-bearing minerals. It forms in arid climates on dumps and in workings of uranium-vanadium mines, likely from the reaction of vanadium-rich solutions with organic materials or ammonia. ## Mineral Associations This mineral co-occurs with other secondary vanadates. At the type locality (St. Jude mine), it was found in association with huemulite, pascoite, gypsum, and hydrated iron oxides. ## Localities The only confirmed occurrence of schindlerite in the world is its type locality – the dumps of the St. Jude mine, Slick Rock district, San Miguel County, Colorado, USA.

Rarity

Extremely rare

For collectors

## Quality Criteria As a micromineral, schindlerite is primarily judged by the quality and size of its crystals, although these rarely exceed fractions of a millimeter. The most desirable specimens are those with well-formed, sharp crystals forming aesthetic, radial aggregates. The intensity and purity of the orange color also contribute to the specimen's attractiveness. The amount of mineral on the rock matrix is also important. ## Popular Localities The only source of schindlerite specimens is the St. Jude mine in Colorado, USA. All specimens available on the collector's market originate from this single location.

Care and storage

## Cleaning The mineral is water-soluble. ABSOLUTELY DO NOT clean it with water, alcohol, or any other liquids. Specimens should only be cleaned mechanically, using a very soft brush or carefully blowing off dust with compressed air from a distance. ## What to Avoid Avoid contact with water and any liquids, which will immediately dissolve and destroy the specimen. The mineral is very sensitive to airborne moisture, which can lead to its slow degradation. Protect it from high temperatures and direct sunlight. ## Storage Schindlerite specimens must be stored in a dry environment. It is recommended to keep them in tightly sealed "perky box" containers along with a desiccant (e.g., silica gel). Storage in low-humidity conditions is crucial for preserving the mineral's integrity.

External references

Sources

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