Euxenite Value, Price, and Jewelry Information

Euxenite

Euxenite is seldom seen in collections. Most collectors would not regard the mineral as facetable, but transparent fragments and areas of crystals have been noted that could cut small gems. Sometimes cabochons are cut by collectors, but these are not very striking. The colors of faceted stones would be too dark to make them appealing.

Euxenite Information

Data Value
Name Euxenite
Colors Black, sometimes with a tinge of brown or green.
Crystallography Orthorhombic. Crystals prismatic, stubby; as aggregates; massive.
Refractive Index 2.06-2.24
Luster Submetallic; vitreous to resinous.
Hardness 5.5 - 6.5
Fracture Conchoidal
Specific Gravity 4.30-5.87 depending on the Ta content and hydration.
Birefringence None.
Cleavage None
Stone Sizes Gems cut from euxenite are almost always small, as the material is seldom transparent.
Luminescence None.
Luminescence Present No
Transparency Translucent to opaque, very rare transparent fragments.
Formula

(Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6

Polycrase: (Y,Ca,Ce,U,Th)(Ti,Nb,Ta)2O6.

Optics

Isotropic due to metamictization. = 2.06-2.24.

Series to Polycrase.

Streak: Grayish, yellow-brown.

Optics: Isotropic due to metamictization. N=2.06-2.24.

Luminescence: None.

Occurrence: In granite pegmatites; also as detrital grains.

California; Colorado; Pennsylvania; Maine.

Norway; Canada; Greenland; Brazil; Finland; Zaire; Madagascar; Australia.

Wyoming: large crystals.

Comments: Euxenite is seldom seen in collections. Most collectors would not regard the mineral as facetable, but transparent fragments and areas of crystals have been noted that could cut small gems. Sometimes cabochons are cut by collectors, but these are not very striking. The colors of faceted stones would be too dark to make them appealing.

Name: From the Greek euxenos (hospitable) because of the many useful elements it contains. Polycrase is from the Greek, meaning mixture of many, also in allusion to the composition.