Xenotime is the principal heavy-REE-phosphate, complementary to monazite which carries the light REEs. It is the dominant economic source of yttrium, dysprosium, terbium and erbium.
Properties
- Formula: (Y,HREE)PO4
- Crystal system: Tetragonal
- Hardness: 4 – 5
- Color: Yellow-brown to reddish-brown, sometimes greenish
- Streak: Pale yellow to white
- Luster: Vitreous to resinous
- Cleavage: Perfect on {100}
- Density: 4.4 – 5.1 g/cm³
Occurrence in China
Xianghualing in Hunan is China’s prime collector locality, producing reddish-brown bipyramidal xenotime crystals on quartz and topaz. Also occurs at Bayan Obo and Maoniuping as REE-suite intergrowths. Globally noted at Novo Horizonte (Brazil) and Hidra Island (Norway).
Identification
Tetragonal bipyramids similar to zircon but softer (H 4-5 vs. zircon 7.5) and lower density. Color overlap with monazite, but tetragonal habit and the {100} cleavage are decisive.
Collector Notes
Forms a critical part of any REE display. Xianghualing specimens are highly sought for their crystal sharpness and chocolate-brown color contrasting with milk-white matrix.
Found at these Localities
- Maoniuping REE Mine (牦牛坪稀土矿)
- Bayan Obo Mine (白云鄂博)
- Xianghualing Mine (香花岭)
- Hunan (湖南)
- Eastern Brazilian Pegmatite Province (巴西东部伟晶岩省)
