Glushinskite

Chemical formula: Mg(C₂)⁶⁺O₄·₂H₂O

Glushinskite is a rare, organic mineral – hydrated magnesium oxalate, forming soft, white or colorless coatings and aggregates.

## Characteristics Glushinskite is a mineral from the humboldtine group, belonging to the class of organic compounds. Chemically, it is hydrated magnesium oxalate. It occurs rarely, most often as soft, earthy or powdery coatings, as well as aggregations of small, poorly formed crystals. Its appearance is usually inconspicuous, resembling chalky or clayey masses. ## Physical Properties This mineral is characterized by very low hardness, 2 on the Mohs scale, which means it can be scratched with a fingernail. It is light, with a density of approximately 1.85 g/cm³. Crystals, if visible, exhibit a vitreous to pearly luster. It is translucent. ## Colors and Varieties Glushinskite is usually creamy white or colorless. No named color or commercial varieties are distinguished for it, due to its rarity and lack of ornamental applications. ## History and Name The mineral was first described in 1960. Its name comes from the Russian mineralogist and petrographer P.I. Glushinsky (1887-1955). The type locality where it was discovered is the Chai-Tumus coal deposits in the Lena River basin, Yakutia (Russia). ## Uses Glushinskite has no industrial significance. Its occurrence is solely of scientific and collector's interest.

Properties

Mohs hardness: 2
Luster: Pearly, Vitreous
Density: 1.85
Transparency: Translucent
Crystal system: Monoclinic

Diagnostic features

## Identification Glushinskite is identified by its exceptional softness (hardness 2), low density, and occurrence in a specific geological environment – on ultramafic rocks or in coal deposits. It typically forms white, chalk-like coatings or small, poorly formed crystals. ## Distinguishing from Similar Minerals It can be confused with other secondary carbonate or sulfate minerals of similar appearance, such as calcite, gypsum, or hydromagnesite. It is distinguished from them by its very low hardness and genesis (it is an organic mineral). Certain identification requires advanced analytical methods, such as X-ray diffraction (XRD). ## Crystal Forms Glushinskite crystals are rare and usually very small, with a tabular or prismatic habit. Most often, it forms granular aggregates, powdery, earthy coatings, and crusts.

Geological environment

## Genesis Glushinskite is a mineral of organic origin. It forms as a result of the interaction of oxalic acid, produced by lichens and other organic matter, with magnesium-rich rocks, such as serpentinites and other ultramafic rocks. It is also found in coal deposits, where it forms as a product of diagenetic or weathering processes. ## Mineral Associations On ultramafic rocks, it co-occurs with rock-forming minerals such as serpentine, as well as other oxalates. At the type locality (coal deposits), no associated minerals have been reported. ## Localities The most important glushinskite localities are its discovery site – the Chai-Tumus coal deposits in Yakutia (Russia). It is also found in serpentinites on Unst Island in the Shetland Islands (Scotland) and in several places in Italy, including the Aosta Valley and Liguria, where it forms due to the action of lichens on ophiolitic rocks.

Rarity

Very rare

For collectors

## Quality Criteria The quality of a glushinskite specimen primarily depends on the degree of crystal development. Samples with visible, even if small, transparent crystals are most highly valued, which is a great rarity. In the case of typical coatings, the abundance of the mineral on the rock matrix and a well-documented locality are important. ## Popular Localities Specimens from the type locality in Russia are historically important but extremely rare in collections. Small but well-defined crystals come from some localities in Italy, where the mineral forms on serpentinites.

Care and storage

## Cleaning Glushinskite specimens are extremely delicate and soft. They should only be cleaned with a very soft brush or a stream of compressed air to remove dust. Avoid contact with water, which can dissolve or damage the mineral. ## What to Avoid Water, acids, detergents, and all other chemicals should be absolutely avoided. The mineral is sensitive to high temperatures and humidity. It should not be subjected to ultrasonic or steam cleaning. ## Storage Glushinskite requires storage in stable conditions, away from moisture and heat sources. It is best kept in a closed, padded display box to protect it from mechanical damage and dust.