| Euxenite | |
|---|---|
 Euxenite fromNorway, around 11 cm of size | |
| General | |
| Category | Oxide minerals |
| Formula | (Y,Ca,Ce,U,Th)(Nb,Ta,Ti) 2O 6 |
| IMA symbol | Eux[1] |
| Strunz classification | 4.DG.05 |
| Crystal system | Orthorhombic |
| Space group | Pcmn (no. 62) |
| Identification | |
| Color | Black, brownish black, greenish black |
| Crystal habit | Massive, anhedral crystals in matrix |
| Twinning | Common on [201] |
| Cleavage | None |
| Fracture | Conchoidal to subconchoidal |
| Mohs scale hardness | 5.5 to 6.5 |
| Luster | Brilliant submetallic, waxy to resinous on fractures |
| Streak | Yellowish, grayish, or reddish brown |
| Diaphaneity | Opaque, translucent on thin edges |
| Specific gravity | 4.7 to 5 |
| Optical properties | Isotropic |
| Refractive index | n = 2.06 – 2.24 |
| Other characteristics | Metamict – originally crystalline, now amorphous due to radiation damage. Radioactive |
| References | [2][3][4] |
Euxenite, oreuxenite-(Y) (the official mineralogical name), is a brownish blackmineral with a metallicluster.
It containscalcium,niobium,tantalum,cerium,titanium,yttrium, and typicallyuranium andthorium, with some othermetals. The chemical formula is(Y,Ca,Ce,U,Th)(Nb,Ta,Ti
2)O
6. It is commonly partiallyamorphous due toradiation damage.
Euxenite forms a continuous series with the titanium richpolycrase-(Y) having the formula(Y,Ca,Ce,U,Th)(Ti,Nb,Ta)
2O
6.
It was first described in 1870 and named for from the Greek (εὔξενος),hospitable orfriendly to strangers, in allusion to the many rare elements that it contains.[4][3]
It occurs ingranitepegmatites and detritalblack sands.[2]
It is found in many locations worldwide, notably its type locality in Jølster, Sunnfjord,Norway.[3] Other locations include theUral Mountains ofRussia;Sweden;Minas Gerais,Brazil; Ampangabe,Madagascar;Ontario, Canada; and inArizona,Wyoming andColorado in the US.[5]
Euxenite is used as anore of therare earth elements it contains. Rare large crystals have also been used in jewelry.[5]
| Oxide minerals |
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| Silicate minerals | |||||
| Other | |||||
