Trebiskyite

Chemical formula: Na₃Mg₂[(Ti⁴⁺V⁵⁺₉)O₂₈]·22H₂O

Trebiskyite is a very rare, hydrated sodium, magnesium, and titanium vanadate, forming aggregates of tiny, yellow crystals.

## Characteristics Trebiskyite is a mineral from the pascoite group, belonging to the vanadate class. It occurs as aggregates of small, bladed or tabular crystals, rarely exceeding 1 mm in length. It also forms crusts and aggregates. Its most characteristic feature is its intense, yellow color. ## Physical Properties This mineral is relatively soft, with a hardness of about 2 on the Mohs scale. It is light, with a density of 2.38 g/cm³. The crystals are translucent and exhibit a pale, yellow streak. The fracture is uneven. ## Colors and Varieties Trebiskyite occurs in a uniform, yellow color. No color varieties or commercial varieties are known. ## History and Name The mineral is named in honor of John Trebisky (1946-2012), an American mineral collector from Arizona, who specialized in microminerals and was the first to find this mineral. It was formally described and approved as a new mineral species in 2013. The type locality, from which the first described specimens originate, is the Pickett Corral mine in Montrose County, Colorado, USA. ## Uses Due to its extreme rarity and small crystal size, trebiskyite has no industrial applications. It is solely an object of interest for collectors specializing in rare minerals and microminerals.

Properties

Mohs hardness
2-0
Streak
pale-yellow
Density
2.38
Fracture
Irregular/Uneven
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Characteristic features of trebiskyite include its intensely yellow color, occurrence as small, bladed crystals forming crusts, and its specific geological environment. The reaction to water (solubility) is also a diagnostic, though destructive, feature. ## Distinguishing from Similar Minerals Trebiskyite can be confused with other yellow secondary vanadium minerals, such as carnotite, tyuyamunite, or pascoite. Differentiation requires advanced analytical methods, such as chemical analysis (EDS) or X-ray diffraction (XRD), due to the presence of magnesium and titanium in trebiskyite's structure. ## Crystal Forms The mineral forms very small, elongated, bladed or tabular crystals, which combine into radial aggregates, rosettes, or form thin crusts on the host rock.

Geological environment

## Genesis Trebiskyite is a secondary mineral, forming in the oxidation zones of uranium-vanadium deposits in sedimentary rocks, mainly sandstones. It forms as a result of the weathering of primary vanadium minerals under low temperature and pressure conditions, in an arid climate. ## Mineral Associations It co-occurs with other secondary vanadate minerals, such as pascoite, sherwoodite, as well as gypsum and montroseite. ## Localities The only confirmed and described locality of trebiskyite in the world is its type locality – the Pickett Corral mine in the Uravan Mineral Belt, Montrose County, Colorado, USA.

Rarity

Very rare

For collectors

## Quality Criteria The quality of a trebiskyite specimen is assessed based on the richness and coverage of the host rock by crystals, as well as their size and habit, although they are always microscopic. The intensity of the yellow color also affects visual appeal. Specimens with well-defined, radial aggregates are more highly valued. ## Popular Localities The only source of specimens is the Pickett Corral mine in Colorado, USA. All specimens available on the collector's market originate from this single locality.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using compressed air to remove dust. Contact with water, especially warm water, can damage or dissolve the mineral. All wet and mechanical cleaning methods (brushes, ultrasonics) should be avoided. ## What to Avoid Contact with water and other liquids, chemicals, acids, and detergents must be strictly avoided. The mineral is sensitive to elevated temperatures, which can lead to its dehydration and destruction. It should be protected from direct sunlight and humidity. ## Storage It is recommended to store specimens in sealed, airtight containers (so-called "micromount boxes") under stable, low-humidity conditions. Due to its softness and fragility, contact with other minerals should be avoided.

External references

Sources

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