Thomasclarkite-(Y)

(repeating unit)(Na, Ce)(Y, REE)(HCO3)(OH)3·4(H2O)IMA symbolTcl-Y[1]Crystal systemMonoclinicCrystal classSphenoidal (2)
(same H-M symbol)Space groupP2IdentificationFormula mass375.77 g/molColorWhite, yellowCrystal habitBlocky crystals, pseudo-tetragonalTwinningCommon on (101)Cleavage[010] Perfect, [101] partingFractureUnevenTenacityVery brittleMohs scale hardness2–3LusterVitreous (glassy)StreakWhiteDiaphaneityTranslucent to transparentSpecific gravity2.30Optical propertiesPseudouniaxial negative 2V (meas.) ≤ 5°Refractive indexnα = 1.40, nβ = 1.540, nγ = 1.540Birefringenceδ = 0.140Other characteristics Radioactive 770 Bq/gReferences[2][3][4]

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

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ http://rruff.geo.arizona.edu/doclib/hom/thomasclarkitey.pdf Handbook of Mineralogy
  3. ^ http://webmineral.com/data/Thomasclarkite-(Y).shtml Webmineral data
  4. ^ http://www.mindat.org/min-7336.html Mindat
  • Mont Saint-Hilaire


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