Wakefieldite-(Ce)

Chemical formula: Ce<sup>3+</sup>V<sup>5+</sup>O<sub>4</sub>

Wakefieldite-(Ce) is a rare vanadate mineral, prized for its microscopic, orange-brown crystals with a tetragonal structure.

## Characteristics Wakefieldite-(Ce) is a cerium vanadate belonging to the xenotime group. It forms very small, most often microscopic crystals, whose size rarely exceeds 1 mm. It usually occurs as single, pyramidal crystals with a square cross-section or as aggregates of such crystals, forming coatings and efflorescences on rock surfaces. Its appearance is distinctive, although due to the small size of the crystals, magnification is necessary for observation. ## Physical Properties This mineral is characterized by a hardness in the range of 4-5 on the Mohs scale. It has a strong, almost adamantine luster. It is opaque or at most translucent in very thin fragments. Its density is high, approximately 5.19 g/cm³. ## Colors and Varieties Wakefieldite-(Ce) most often takes on colors ranging from orange and reddish-brown to brown and almost black. No named varieties are distinguished. ## History and Name The mineral's name comes from its discovery locality at the Evans-Lou mine, located in the municipality of Wakefield, Quebec, Canada. The -(Ce) suffix in the name indicates the dominant rare-earth element in its composition, which is cerium. The mineral was described and approved as a new species in 1977. ## Uses Wakefieldite-(Ce) has no industrial applications. Its significance is purely scientific and as a collector's item, being of interest to specialized collectors of rare minerals and micromounts.

Properties

Mohs hardness
4-5
Luster
Adamantine
Streak
Light brown
Density
5.19
Cleavage
Good on {101}
Fracture
Uneven
Transparency
Translucent to opaque
Crystal system
Tetragonal

Diagnostic features

## Identification Wakefieldite-(Ce) is identified by its characteristic crystal form – sharp, tetragonal bipyramids – and its intense, orange-brown color. Hardness, high density, and strong luster are also helpful features. Due to its small size, final identification often requires advanced analytical methods, such as EDS spectroscopy. ## Distinguishing from Similar Minerals It can be confused with other minerals from the xenotime group, such as xenotime-(Y) or wakefieldite-(Y), from which differentiation is practically only possible through chemical analysis of elemental composition. Visually, it may resemble some garnets or zircon, but it differs from them in crystal form and occurrence environment. ## Crystal Forms Crystals are usually very small and take the form of simple, sharp tetragonal bipyramids. More rarely, they form prismatic crystals terminated by pyramidal faces. They occur as single, overgrown crystals or as small aggregates and coatings.

Geological environment

## Genesis Wakefieldite-(Ce) is a secondary mineral, formed in the oxidation zones of ore deposits, or a mineral of hydrothermal origin. At its type locality (Evans-Lou mine, Canada), it occurs in syenite pegmatites, where it formed as a result of hydrothermal processes acting on primary rare-earth minerals. ## Mineral Associations This mineral co-occurs with minerals such as: quartz, microcline, albite, aegirine, zircon, thorite, allanite-(Ce), montmorillonite, as well as other rare secondary minerals. ## Localities The most important and best-documented occurrences of this mineral are the Evans-Lou mine in Quebec (Canada), from which classic specimens originate. It has also been reported in Switzerland (Fianel mine, Ferrera Valley), Italy (Buca della Vena, Tuscany), and the Clara mine in the Black Forest (Germany).

Rarity

Very rare

For collectors

## Quality Criteria Specimens with sharp, well-formed crystals of intense, orange or reddish-brown color are most valued by collectors. Contrast with a light matrix rock on which the crystals are embedded is important. Due to the microscopic nature of the mineral, the size of the crystals, even if only a fraction of a millimeter, significantly increases the value of the specimen. Rich aggregates of many crystals are more desired than single individuals. ## Popular Localities The type locality – the Evans-Lou mine in Quebec, Canada – is considered classic and provides the best specimens. Specimens from this locality serve as the standard for the species.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to the fragility and small size of the crystals, mechanical cleaning, including brushes, should be avoided. The use of water is not recommended. ## What to Avoid Contact with chemicals, especially acids, which can damage the mineral, should be avoided. The crystals are fragile and sensitive to ultrasound and mechanical shocks. It should not be subjected to sudden temperature changes. ## Storage The safest storage method is to place the specimen in a "micromount" box, which protects the delicate crystals from physical damage and dust. Exposure to moisture should be avoided.

External references

Sources

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