Wakefieldite-(Y)

Chemical formula: YV⁵⁺O₄

Wakefieldite-(Y) is a rare yttrium vanadate, forming small, tetragonal crystals with a yellowish hue, valued by collectors of rare minerals.

## Characteristics Wakefieldite-(Y) is an yttrium vanadate belonging to the xenotime group. It occurs as very small, individual crystals with a tetragonal structure or as aggregates and coatings. Its crystals rarely exceed 1 mm in size. It is a secondary mineral, forming in the late stages of pegmatite crystallization or as a result of hydrothermal processes. ## Physical Properties This mineral is characterized by a hardness of 5 on the Mohs scale. It has a luster described as vitreous to resinous. It is translucent to opaque. Due to the small size of the crystals, accurate determination of physical properties can be difficult. ## Colors and Varieties Wakefieldite-(Y) most commonly exhibits colors ranging from pale yellow and canary yellow to yellowish-brown. No named varieties are distinguished, and color differences result from minor admixtures of other rare earth elements that can substitute yttrium in the crystal structure. ## History and Name The mineral's name refers to its discovery location in 1968 – the Evans-Lou mine, situated in the municipality of Saint-Pierre-de-Wakefield in Quebec, Canada. The suffix "-(Y)" indicates the dominant rare earth element in its composition – yttrium. It was described by D. Hogarth and J.E. Miles. ## Applications Wakefieldite-(Y) has no industrial applications. Its significance is purely scientific and as a collector's item, as a rare representative of rare earth element vanadates.

Properties

Mohs hardness: 5
Luster: Resinous to vitreous
Streak: White to pale yellow
Density: 0
Transparency: Translucent to opaque
Crystal system: Tetragonal

Diagnostic features

## Identification Field identification of wakefieldite-(Y) is practically impossible due to its rarity and small crystal size. In a collection, it can be preliminarily recognized by its tetragonal crystal form, yellowish coloration, and association with other pegmatitic minerals. Definitive identification requires advanced analytical methods, such as energy-dispersive X-ray spectroscopy (EDS/EDX) to confirm the chemical composition (presence of yttrium and vanadium). ## Distinguishing from Similar Minerals Wakefieldite-(Y) can be confused with other minerals from the xenotime group, such as xenotime-(Y) or chernovite-(Y), which have similar form and color. Distinguishing them without chemical analysis is impossible. It may also resemble other small, yellow secondary minerals. ## Crystal Forms It forms simple, prismatic or dipyramidal crystals with a square cross-section, typical of the tetragonal system. Crystals are usually very small, often below 1 mm. It also occurs as granular aggregates or as coatings on other minerals.

Geological environment

## Genesis Wakefieldite-(Y) is a secondary mineral. It forms in the late stages of crystallization in granitic pegmatites, often as a result of hydrothermal processes or weathering of primary minerals containing yttrium and vanadium. It can also crystallize in rock fractures and vugs. ## Mineral Associations It often co-occurs with other minerals typical of pegmatites and hydrothermal zones, such as quartz, albite, microcline, annite (biotite), zircon, xenotime-(Y), monazite, as well as rarer minerals, e.g., montroydite. ## Localities The most important and type locality is the Evans-Lou mine in Quebec (Canada). Other confirmed localities include the Bellerberg mine in Eifel (Germany), some pegmatites in Norway (e.g., in the Tvedalen area), Switzerland (Binn Valley), and Japan (Gozaisho mine, Fukushima Prefecture).

Rarity

Very rare

For collectors

## Quality Criteria Specimens with well-formed, sharp crystals of intense, canary-yellow color are most valued by collectors. Contrast with the rock matrix and the presence of associated minerals are also important. Due to its rarity, even microscopic but well-formed crystals are considered valuable. ## Popular Localities Specimens from the type locality, the Evans-Lou mine in Canada, are the most sought-after and represent a classic for this mineral. Well-formed crystals from the German Eifel volcanic complex are also highly prized.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using a soft brush to remove dust. Due to the small and fragile crystals, wet cleaning or ultrasonic cleaning is not recommended. ## What to Avoid Avoid contact with acids and other chemicals that may damage the mineral's surface. Do not heat specimens or expose them to sudden temperature changes. Prolonged exposure to strong sunlight may not be advisable. ## Storage It is recommended to store specimens in stable conditions, in sealed "micromount" boxes, which protect them from dust, moisture, and mechanical damage. Due to the small size of the crystals, avoid placing them in direct contact with other, harder minerals.