Radekškodaite-(Ce)

Chemical formula: (CaCe³⁺₅)(Al₄Fe²⁺)[Si₂O₇][SiO₄]₅O(OH)₃

Radekškodaite-(Ce) is a rare silicate of the tschernichite group, characterized by a greenish-brown color and occurrence in Russian pegmatites.

## Characteristics Radekškodaite-(Ce) is a complex silicate belonging to the radekškodaite group (formerly known as the tschernichite group). It forms subhedral (imperfectly formed) grains up to 1 cm in size. Its characteristic features include a greenish-brown color and occurrence in association with other rare minerals. ## Physical Properties This mineral has a hardness of 6.5 on the Mohs scale. It exhibits a vitreous luster and is translucent. Its density, calculated from crystallographic data, is 4.65 g/cm³. It possesses good cleavage in one direction and imperfect cleavage in another, and its fracture is uneven. ## Colors and Varieties The observed color of this mineral is a uniform, greenish-brown. No color varieties or commercial forms have been distinguished. ## History and Name The mineral is named in honor of Radek Škoda (born 1979), a Czech mineralogist from the Czech Geological Survey, for his contributions to rare-earth element mineralogy. The suffix -(Ce) refers to the dominant rare-earth element in its composition – cerium. The mineral was approved by the IMA in 2018 (IMA2018-002), and its description was published in 2019. The type locality is Mochalin Log in Russia. ## Uses Due to its extreme rarity, radekškodaite-(Ce) has no industrial applications. It is solely an object of scientific interest and a collector's item for specialized micromineral collectors.

Properties

Mohs hardness
6.5
Luster
Vitreous
Streak
Brown
Density
4.651
Cleavage
Good in one direction (possibly {100}), imperfect in another.
Fracture
Irregular/Uneven
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of radekškodaite-(Ce) under amateur conditions is practically impossible. It requires advanced analytical methods, such as electron spectroscopy (EDS/WDS) to confirm chemical composition and X-ray diffraction (XRD) to determine crystal structure. Preliminary indications may include its greenish-brown color, mineral association, and locality. ## Distinguishing from similar minerals It can be confused with other brown silicates from the epidote group or with vesuvianite, which occur in similar environments. Definitive differentiation is only possible through chemical analysis, which will show the presence and dominance of cerium and the characteristic ratio of other elements. ## Crystal forms This mineral forms imperfectly developed (subhedral) grains, which may occur as aggregates. Well-formed, freestanding crystals have not been observed.

Geological environment

## Genesis This is an igneous mineral, crystallizing in the late stages of syenite pegmatite evolution. It forms in an environment enriched in rare-earth elements, aluminum, and iron. ## Mineral associations At the type locality (Mochalin Log), it co-occurs with minerals such as albite, microcline, quartz, annite (iron-rich biotite), tschernichite-(Ce), fluorite, pyrochlore, zircon, ilmenite, and fergusonite-(Y). ## Localities The only confirmed occurrence of radekškodaite-(Ce) in the world is its type locality – Mochalin Log, near the city of Kyshtym, in the Chelyabinsk Oblast in the Southern Urals, Russia.

Rarity

Extremely rare

For collectors

## Quality criteria The quality of a specimen primarily depends on the size of the radekškodaite-(Ce) grain and its association with other minerals. The most desirable specimens are those where the mineral is clearly visible, has an intense color, and contrasts with the surrounding rock matrix. Due to its mode of occurrence, crystal purity and form are not key criteria. ## Popular localities The only source of specimens is the type locality in Russia. Material from this locality is extremely difficult to acquire and appears on the collector's market very sporadically, mainly circulating among specialized collectors and research institutions.

Care and storage

## Cleaning Cleaning is recommended only with a soft brush to remove dust. The use of water, especially with detergents, is discouraged due to a lack of data on its reactivity. ## What to avoid Avoid contact with chemicals, especially acids, which can damage the mineral. It should also be protected from ultrasound, high temperatures, and sudden temperature changes. ## Storage Specimens should be stored in stable conditions, in a sealed "micromount" box, to protect them from dust and mechanical damage. It is not sensitive to light, but prolonged exposure to moisture should be avoided.

External references

Sources

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