Saranchinaite

Chemical formula: Na₂Cu²⁺(S⁶⁺O₄)₂

Saranchinaite is a very rare, water-soluble sodium and copper sulfate, forming intensely blue, prismatic crystals.

## Characteristics Saranchinaite is a hydrated sodium and copper sulfate, distinguished by its unusual, intense, azure-blue color. It forms elongated, prismatic crystals, often gathered in radial or acicular aggregates. Due to its water solubility, it is an unstable mineral in humid environments and requires special protection in collections. Its crystals are usually small, reaching up to several millimeters in length, and are characterized by a strong vitreous luster. ## Physical Properties This mineral is relatively soft, with a hardness of about 2.5 on the Mohs scale. It has a vitreous luster and is transparent to translucent. Its density is approximately 2.77 g/cm³. A characteristic feature is its complete solubility in water, which is crucial for its identification and storage. ## Colors and Varieties Saranchinaite occurs in a uniform, azure-blue to blue color. No color or commercial varieties are known. ## History and Name The mineral's name comes from its discovery locality – the Saranchinovskoe (Saranovskaya) mine in the Middle Urals, Russia. It was officially recognized by the International Mineralogical Association (IMA) in 2017. It was described by Russian mineralogists, including Igor V. Pekov. ## Applications Saranchinaite has no industrial applications. Its significance is purely scientific and collectible, being an object of desire for specialized collectors of rare minerals.

Properties

Mohs hardness
2.5
Luster
Vitreous
Streak
Light blue
Density
2.77
Cleavage
Perfect on {110}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification The key diagnostic feature of saranchinaite is its complete solubility in water. Its intensely azure-blue color, vitreous luster, and prismatic or acicular crystal habit are also very characteristic. Reaction to moisture is the simplest test, though destructive. ## Differentiation from Similar Minerals Saranchinaite can be confused with other secondary copper sulfates, such as chalcanthite. Chalcanthite is also blue and water-soluble, but it crystallizes in the triclinic system (saranchinaite in monoclinic) and has a different chemical composition (it is a hydrated copper sulfate, without sodium). Accurate differentiation requires advanced chemical (EDS) or crystallographic (XRD) analyses. ## Crystal Forms Saranchinaite forms elongated, prismatic crystals with a nearly square cross-section. They often occur as radial or chaotically arranged acicular aggregates. Single, well-formed crystals are rare.

Geological environment

## Genesis Saranchinaite is a secondary mineral, forming in the oxidation zones of ore deposits. It forms as a result of the activity of sulfate-rich waters reacting with copper and sodium compounds. Its formation is associated with the weathering processes of primary minerals under specific chemical conditions. It is an unstable mineral, forming in a dry microclimate, e.g., in mine workings. ## Mineral Associations At its type locality (Saranchinovskoe mine), it co-occurs with chalcanthite, kröhnkite, blödite, gypsum, tenorite, and other rare sulfates. ## Localities The only confirmed and well-documented locality for saranchinaite in the world is its type locality: the Saranchinovskoe (Saranovskaya) chromite mine in Perm Krai, Middle Urals, Russia.

Rarity

Very rare

For collectors

## Quality Criteria The most prized saranchinaite specimens are those with well-formed, transparent crystals of an intense blue color. Rich acicular or radial aggregates on a contrasting rock matrix enhance their attractiveness. Due to the mineral's rarity, any specimen with visible crystals is valuable. The size of the crystals and the entire specimen is crucial for its value. ## Popular Localities The only source of collectible specimens is the Saranchinovskoe mine in Russia. This mineral is not known from any other locality in the world, which makes it extremely desirable and difficult to acquire.

Care and storage

## Cleaning ABSOLUTELY DO NOT clean saranchinaite with water or any liquids, as it is completely soluble. Specimens can only be cleaned mechanically, using a very soft brush or compressed air from a safe distance to remove dust. ## What to Avoid Avoid contact with water, water vapor, and high humidity, which can cause the mineral to dissolve and be destroyed. It must be protected from all chemicals. It should not be heated. ## Storage Saranchinaite specimens must be stored in a dry environment. The best solution is a sealed, transparent container (a so-called perky box) with a desiccant (e.g., silica gel). Avoid exposing it to direct heat sources and moisture.

External references

Sources

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