Euxenite
| Euxenite | |
|---|---|
 Euxenite from Norway, around 11 cm of size |
|
| General | |
| Category | Oxide minerals |
| Formula (repeating unit) |
(Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 |
| Strunz classification | 04.DG.05 |
| Identification | |
| Color | Black, brownish black,greenish black |
| Crystal habit | Massive, anhedral crystals in matrix |
| Crystal system | Orthorhombic |
| 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 | [1][2][3] |
Euxenite or euxenite-(Y) (a correct mineralogical name) is a brownish black mineral with a metallic luster.
Contents |
Chemistry [edit]
It contains calcium, niobium, tantalum, cerium, titanium, yttrium, and typically uranium and thorium, with some other metals. The chemical formula is: (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6. It is commonly partially amorphous due to radiation damage.
Name and discovery [edit]
It was first described in 1870 and named for from the Greek (εύξεινος), hospitable or friendly to strangers, in allusion to the many rare elements that it contains.[3][2]
Occurrence [edit]
It occurs in granite pegmatites and detrital black sands.[1]
It is found in many locations worldwide, notably its type locality in Jølster, Sunnfjord, Norway.[2] Other locations include include the Ural Mountains of Russia; Sweden; Minas Gerais, Brazil; Ampangabe, Madagascar; Ontario, Canada; and in Arizona, Wyoming and Colorado in the U. S. A.[4]
Use [edit]
Euxenite is used as an ore of the rare earth elements it contains. Rare large crystals have also been used in jewelry.[4]
References [edit]
- ^ a b http://rruff.geo.arizona.edu/doclib/hom/euxenitey.pdf Minderal Handbook
- ^ a b c http://webmineral.com/data/Euxenite-(Y).shtml Webmineral data
- ^ a b http://www.mindat.org/min-1425.html Mindat
- ^ a b http://www.galleries.com/minerals/oxides/euxenite/euxenite.htm Mineral Galleries
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