| Euxenite | |
| Category: | Oxide minerals |
| Imasymbol: | Eux[1] |
| Strunz: | 4.DG.05 |
| Symmetry: | Pcmn (no. 62) |
| Color: | Black, brownish black, greenish black |
| Habit: | Massive, anhedral crystals in matrix |
| Twinning: | Common on [201] |
| Cleavage: | None |
| Fracture: | Conchoidal to subconchoidal |
| Mohs: | 5.5 to 6.5 |
| Luster: | Brilliant submetallic, waxy to resinous on fractures |
| Refractive: | n = 2.06 – 2.24 |
| Opticalprop: | Isotropic |
| Streak: | Yellowish, grayish, or reddish brown |
| Gravity: | 4.7 to 5 |
| Diaphaneity: | Opaque, translucent on thin edges |
| Other: | Metamict – originally crystalline, now amorphous due to radiation damage. Radioactive |
| References: | [2] [3] [4] |
Euxenite, or euxenite-(Y) (the official mineralogical name), is a brownish black mineral with a metallic luster.
It contains calcium, niobium, tantalum, cerium, titanium, yttrium, and typically uranium and thorium, with some other metals. The chemical formula is . It is commonly partially amorphous due to radiation damage.
Euxenite forms a continuous series with the titanium rich polycrase-(Y) having the formula .
It was first described in 1870 and named for from the Greek (εὔξενος), hospitable or friendly to strangers, in allusion to the many rare elements that it contains.[4] [3]
It occurs in granite pegmatites and detrital black sands.[2]
It is found in many locations worldwide, notably its type locality in Jølster, Sunnfjord, Norway.[3] Other locations include the Ural Mountains of Russia; Sweden; Minas Gerais, Brazil; Ampangabe, Madagascar; Ontario, Canada; and in Arizona, Wyoming and Colorado in the US.[5]
Euxenite is used as an ore of the rare earth elements it contains. Rare large crystals have also been used in jewelry.[5]