Cuprodobrovolskyite

Chemical formula: Na<sub>4</sub>Cu<sup>2+</sup>(S<sup>6+</sup>O<sub>4</sub>)<sub>3</sub>

A blue sodium copper sulfate, crystallizing in the monoclinic system, occurring as small tabular crystals in volcanic fumaroles.

## Characteristics Kupodobrowolskyite is a sodium copper sulfate that forms very small, tabular or lath-like crystals, rarely exceeding 0.2 mm. They usually occur as loose aggregates, clusters, or crusts on volcanic scoria. The mineral is characterized by an intense blue color. ## Physical Properties Kupodobrowolskyite 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 measured. ## Colors and Varieties This mineral occurs in a uniform, light blue to blue color. No varieties have been distinguished. ## History and Name Kupodobrowolskyite was discovered in the products of fumarolic activity of Tolbachik volcano in Kamchatka, Russia. It was officially recognized as a new mineral by the International Mineralogical Association (IMA) in 2013 (IMA2013-049). Its name honors the Russian mineralogist and petrographer Gleb Vladimirovich Dobrovolsky (1915-2013) and indicates the presence of copper (Latin: *cuprum*) in its chemical composition.

Properties

Luster
Vitreous
Streak
Light blue
Cleavage
Perfect on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Kupodobrowolskyite is identified based on its unique occurrence environment (volcanic fumaroles), characteristic blue color, tabular form of small crystals, and co-occurrence with other volcanic sulfates. Confirmation requires advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS). ## Distinguishing from Similar Minerals It can be confused with other blue sulfates from the sublimation mineral group, such as chalcanthite, but differs from them in crystal habit and chemical composition. Unlike chalcanthite, kupodobrowolskyite forms tabular crystals in the monoclinic system, not triclinic. ## Crystal Forms It forms thin, tabular or lath-like crystals with hexagonal or rhombic outlines, often gathered into irregular aggregates and crusts.

Geological environment

## Genesis Kupodobrowolskyite is a mineral of volcanic origin, formed by sublimation from volcanic gases in high-temperature fumaroles (above 400°C). It crystallizes directly from the gas phase on the surface of volcanic rocks. ## Mineral Associations This mineral co-occurs with other rare sulfates and chlorides formed in fumarolic environments, such as chalcocyanite, tenorite, hematite, langbeinite, aphthitalite, wulfenite, palmierite, krasheninnikovite, and arcanite. ## Localities The only confirmed locality of kupodobrowolskyite in the world is its type locality - the "Arsenatnaya" and "Yadovitaya" fumarole fields at the second cinder cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption in Kamchatka, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria As a "micromount" type mineral, the value of a specimen is primarily determined by the abundance and quality of crystals visible under magnification. Most prized are specimens with well-formed, clearly separated crystals of intense blue color, deposited on a contrasting matrix. Association with other rare minerals from this locality is also important.

Care and storage

## Cleaning Due to the extreme delicacy and small size of the crystals, mechanical cleaning is not recommended. Specimens should be protected from dust by storing them in closed containers. ## What to Avoid The mineral is water-soluble, so contact with water and moisture must be strictly avoided. All chemicals, ultrasonics, and sudden temperature changes should also be avoided. ## Storage Kupodobrowolskyite specimens should be stored in a dry place, preferably in tightly sealed "micromount" boxes or specialized cabinets with humidity control, to prevent its decomposition.

Sources

Read more