Wakefieldite (YVO4) occurs in a zoned granite pegmatite near Wakefield Lake, Quebec. Wakefieldite has been found in the quartz core, giant perthite-quartz zone, and on the mine dump. It is considered a secondary mineral, possibly derived by leaching of hellandite, and precipitated from warm alkaline solutions.
About 60 minerals, including compounds of Y, U, Th, Nb, and Bi occur in the pegmatite; 9 of these are unidentified. Pure wakefieldite could not be obtained for chemical analysis but Y and V are important constituents. YVO4 is also found in solid solution (about 10 wt %) in thorogummite at this locality.
The X-ray pattern is similar to synthetic YVO4. The mineral has the zircon structure, space group I41,/amd, a = 7.105 ± 0.003 Å, c = 6.29 ± 0.01 Å, Z = 4. Strongest lines are 4.74 (17), 3.56 (100), 2.66 (50), 2.51 (30), 2.21 (25), 1.824 (75), 1.774 (20).
The mineral is pulverulent and fills cavities in quartz. The color varies from pale tan to yellow. Synthetic YVO4 is optically uniaxial, positive with ω = 2.00, ∈ = 2.14; ρ (calc) = 4.25.