Earlandite
(repeating unit)[Ca3(C6H5O7)2(H2O)2]·2H2O IMA symbol Ear[1] Strunz classification 10.AC.15 Crystal system Triclinic Space group P1 (No. 2) Unit cell a = 5.9466(4), b = 10.2247(8)
c = 16.6496(13) [Å]; Z = 2 Identification Color White, pale yellow Crystal habit Nodular Streak White Diaphaneity Transparent Specific gravity 1.80–1.95 (measured), 2.00 (calculated) Optical properties Biaxial (+) Refractive index nα = 1.515
nβ = 1.530
nγ = 1.580 Birefringence δ = 0.065 2V angle 60° Diagnostic features Fine-grained and wart-like nodule crystal habit Solubility Insoluble References [2][3][4][5]
c = 16.6496(13) [Å]; Z = 2
nβ = 1.530
nγ = 1.580
Earlandite, [Ca3(C6H5O7)2(H2O)2]·2H2O, is the mineral form of calcium citrate tetrahydrate. It was first reported in 1936 and named after the English microscopist and oceanographer Arthur Earland FRSE. Earlandite occurs as warty fine-grained nodules ca. 1 mm in size in bottom sediments of the Weddell Sea, off Antarctica.[4] Its crystal symmetry was first assigned as orthorhombic, then as monoclinic, and finally as triclinic.[2]
References
- ^ 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.
- ^ a b Herdtweck, Eberhardt; Kornprobst, Tobias; Sieber, Roland; Straver, Leo; Plank, Johann (2011). "Crystal Structure, Synthesis, and Properties of tri-Calcium di-Citrate tetra-Hydrate [Ca3(C6H5O7)2(H2O)2]·2H2O". Z. Anorg. Allg. Chem. 637 (6): 655–659. doi:10.1002/zaac.201100088.
- ^ Earlandite. Mindat.org
- ^ a b Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (2003). "Earlandite". Handbook of Mineralogy (PDF). Vol. V (Borates, Carbonates, Sulfates). Chantilly, VA, US: Mineralogical Society of America. ISBN 0962209740.
- ^ Earlandite. Webmineral
Bibliography
- Palache, P.; Berman H.; Frondel, C. (1960). "Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)" John Wiley and Sons, Inc., New York, pp. 1105-1106.