Thomasclarkite-(Y)
Thomasclarkite-(Y) | |
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Thomasclarkite-(Y) | |
General | |
Category | Carbonate mineral |
Formula (repeating unit) | (Na, Ce)(Y, REE)(HCO3)(OH)3·4(H2O) |
Crystal system | Monoclinic |
Identification | |
Formula mass | 375.77 gm |
Color | White, yellow |
Crystal habit | Blocky crystals, pseudo-tetragonal |
Crystal symmetry |
Monoclinic - sphenoidal H-M symbol (2) Space group: P 2 |
Twinning | Common on (101) |
Cleavage | [010] Perfect, [101] Parting |
Fracture | Uneven |
Tenacity | Very brittle |
Mohs scale hardness | 2-3 |
Luster | Vitreous (Glassy) |
Streak | white |
Diaphaneity | Translucent to transparent |
Specific gravity | 2.30 |
Optical properties | pseudouniaxial negative 2V(meas.) ≤ 5° |
Refractive index | α= 1.40, β= 1.540, γ= 1.540 |
Birefringence | δ = 0.140 |
Other characteristics | Radioactivity 770 Bq/g |
References | [1][2][3] |
Thomasclarkite-(Y) is a rare mineral which was known as UK-93 until 1997, when it was renamed in honour of Thomas H. Clark (1893–1996), McGill University professor. The mineral is one of many rare earth element minerals from Mont Saint-Hilaire. The only reported occurrence is in an alkalic pegmatite dike in an intrusive gabbro-nepheline syenite.
See also
References
- ↑ http://rruff.geo.arizona.edu/doclib/hom/thomasclarkitey.pdf Handbook of Mineralogy
- ↑ http://webmineral.com/data/Thomasclarkite-(Y).shtml Webmineral data
- ↑ http://www.mindat.org/min-7336.html Mindat
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