Percleveite-(Ce)

Chemical formula: Ce³⁺₂Si₂O₇

Perkleveite-(Ce) is a rare cerium silicate, forming tiny, transparent, yellowish-gray crystals found in skarns.

## Characteristics Perkleveite-(Ce) is a mineral belonging to the sorosilicate group. It typically forms very small, tabular or prismatic crystals, rarely exceeding a fraction of a millimeter. Its appearance is inconspicuous, and specimens are primarily of scientific importance and for specialized collectors of rare minerals. ## Physical Properties This mineral is characterized by a hardness of 6 on the Mohs scale, placing it on par with orthoclase. It has a relatively high density of 5.21 g/cm³, resulting from its high cerium content. The crystals exhibit a vitreous luster and are transparent. ## Colors and Varieties The observed colors of perkleveite-(Ce) are most often yellowish-gray and white. Due to its rarity and microscopic crystal size, no distinct color varieties or commercial forms are recognized. ## History and Name The mineral's name refers to Per Teodor Cleve (1840-1905), a Swedish chemist and mineralogist who studied rare earth elements. The suffix "-(Ce)" indicates the dominant rare earth element in its composition – cerium. The mineral was first described based on material from its historic type locality. ## Uses Perkleveite-(Ce) has no industrial applications. Its significance is limited to scientific research in the field of mineralogy and crystal chemistry of rare earth silicates, and to advanced micromineral collecting.

Properties

Mohs hardness
6
Luster
Vitreous
Streak
white
Density
5.21
Cleavage
along {001}
Fracture
Uneven
Transparency
Transparent
Crystal system
Tetragonal

Diagnostic features

## Identification Identification of perkleveite-(Ce) is impossible without advanced analytical methods, such as energy-dispersive X-ray spectroscopy (EDS) or X-ray diffraction (XRD), due to its microscopic size and inconspicuous appearance. Preliminary identification in a collection relies on a label from a confirmed locality. ## Distinguishing from Similar Minerals It can be confused with many other rare earth silicates found in similar environments, such as cerite-(Ce), allanite-(Ce), or gadolinite-(Ce). Visual distinction is unfeasible – it requires specialized analysis of chemical composition and crystal structure. ## Crystal Forms Perkleveite-(Ce) crystals are very small, typically tabular or short-prismatic. They crystallize in the tetragonal system.

Geological environment

## Genesis Perkleveite-(Ce) is a mineral of metamorphic origin. It forms in skarns, which are carbonate rocks contact-metamorphosed by intruding hot, silica-rich solutions. Its formation is associated with metasomatism and the concentration of rare earth elements. ## Mineral Associations This mineral coexists with other minerals typical of skarns and rare earth-rich pegmatites. At its type locality, it has been found in association with tremolite, fluorite, cerite-(Ce), bastnäsite-(Ce), and chalcopyrite. ## Localities The only confirmed and described locality for perkleveite-(Ce) worldwide is the historic Bastnäs mines in the Riddarhyttan area (Skinnskatteberg municipality, Västmanland region) in Sweden. This is its type locality.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a perkleveite-(Ce) specimen is primarily assessed based on the confirmation of its identity using analytical methods. Its value is enhanced by the presence of well-formed, even if microscopic, crystals on a rock matrix, as well as a rich association of accompanying minerals. Crystal size is crucial, and any specimen with crystals visible to the naked eye would be an anomaly. ## Popular Localities The only source of collector specimens is the type locality – the Bastnäs mines in Sweden. Material from this location is extremely difficult to acquire and appears on the market very rarely, mainly circulating among specialized collectors.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to the microscopic size of the crystals and their fragility, any form of mechanical or chemical cleaning, including the use of water, is discouraged. ## What to Avoid Avoid contact with chemicals, acids, and detergents. The crystals are fragile and sensitive to shocks and ultrasound. Specimens should not be subjected to sudden temperature changes. ## Storage Perkleveite-(Ce) specimens, as microminerals, should be stored in specialized, sealed "micromount" boxes that protect them from dust, moisture, and mechanical damage. Display is only possible under a microscope.

External references

Sources

Read more