Bluestreakite

Chemical formula: K₄Mg₂[(V₄+₂V₅+₈)O₂₈]·₁₄H₂O

Bluestreakite is a very rare, hydrated potassium magnesium vanadate, forming characteristic blue coatings and aggregates.

## Characteristics Bluestreakite is a secondary mineral, occurring as microscopic, platy or acicular crystals, which usually form rosetted aggregates, spherulites, or thin coatings on the host rock. Individual crystals are too small to be seen with the naked eye. Its most characteristic feature is its intense, dark blue color, which distinguishes it in its occurrence. ## Physical Properties Crystals are flexible and exhibit a silky luster. Due to the microscopic size of the crystals and their occurrence as thin coatings, determining many physical properties, such as hardness or density, is difficult. The density calculated from the formula and unit cell parameters is 2.49 g/cm³. ## Colors and Varieties This mineral is monochromatic – it occurs exclusively in dark blue. It has no known varieties. ## History and Name Bluestreakite was described as a new mineral in 2014 by Anthony R. Kampf and his team. The name comes from the Bluestreak Mine in Montrose County, Colorado (USA), which is its type locality. The mine's name refers to the "blue streaks" that this mineral forms on the surface of uraniferous rocks. ## Applications Bluestreakite has no industrial application. It is of scientific and collector's interest only as a very rare mineral.

Properties

Mohs hardness: 1
Luster: Silky
Streak: Light blue
Density: 2.49
Cleavage: Perfect on {001}
Fracture: Uneven
Transparency: Translucent
Crystal system: Monoclinic

Diagnostic features

## Identification The characteristic features of bluestreakite are its intensely blue color and its occurrence in the form of radial aggregates, rosettes, and coatings on sandstones. The silky luster of the aggregates is also helpful in identification. ## Distinguishing from Similar Minerals Bluestreakite can be confused with other secondary blue vanadium minerals, such as sherwoodite or lasalite. Definitive differentiation requires advanced analytical methods, such as X-ray diffraction (XRD) or chemical analysis (EDS), as these minerals often co-occur and are visually almost identical. ## Crystal Forms The mineral forms very small, platy crystals, elongated along the [010] axis and flattened parallel to {001}. These crystals combine into characteristic radial aggregates, rosettes, and spherulites, and also form thin coatings on the rock surface.

Geological environment

## Genesis Bluestreakite is a secondary mineral, formed in the oxidation zone of uranium-vanadium deposits in sandstones. It forms as a result of the weathering of primary ore minerals under low-temperature conditions. ## Mineral Associations This mineral co-occurs with other rare vanadates, such as lasalite, magnesiopascoite, pascoite, sherwoodite, as well as gypsum. ## Localities The only confirmed and described occurrence of bluestreakite in the world is its type locality – the Bluestreak Mine, located in Bull Canyon, Uravan District, Montrose County, Colorado, USA.

Rarity

Very rare

For collectors

## Quality Criteria The most valued bluestreakite specimens are those that have rich, well-formed, and undamaged crystalline aggregates of intense blue color, contrasting with the light host rock (sandstone). The extent of the mineral's coverage on the rock surface is a key factor influencing value. ## Popular Localities The only source of collector specimens is the Bluestreak Mine in Colorado, USA. This mineral is not commercially mined, and specimens appearing on the market come from limited, specialized prospecting.

Care and storage

## Cleaning Specimens of bluestreakite should not be cleaned wet. The mineral is potentially water-soluble. A soft brush or compressed air from a safe distance can be used to remove dust. ## What to Avoid Contact with water, acids, and other chemicals must be strictly avoided. The mineral is sensitive to changes in humidity and temperature. It should not be heated or exposed to direct sunlight, which can cause dehydration and damage. ## Storage Specimens should be stored in stable conditions, preferably in closed, airtight containers (e.g., "membrane box" or "perky box"), which protect against dust, moisture, and mechanical damage. Due to the fragility and small size of the crystals, they should be handled with the utmost care.

Sources

IMA Mineral List (CNMNC)