Lansfordite

(repeating unit)MgCO3·5H2OIMA symbolLfd[1]Strunz classification5/D.01-30Dana classification15.1.6.1Crystal systemMonoclinicSpace groupP21/c (No. 14)Unit cella=7.3458 Å, b=7.6232 Å, c=12.4737 Å, β=101.722°IdentificationFormula mass174.39ColourColourless, white after exposureCrystal habitCrystals, stalactites terminated by crystal faces, efflorescences, parallel growths.CleavagePerfect, DistinctMohs scale hardness2.5LusterVitreous (if fresh)StreakWhiteDiaphaneityTranslucent, opaque after exposureSpecific gravity1.6Density1.6Birefringence0.042

Lansfordite is a hydrated magnesium carbonate mineral with composition: MgCO3·5H2O.[2] Landsfordite was discovered in 1888 in a coal mine in Lansford, Pennsylvania. It crystallizes in the monoclinic system (space group P21/c[3]) and typically occurs as colorless to white prismatic crystals and stalactitic masses.[4] It is a soft mineral, Mohs hardness of 2.5, with a low specific gravity of 1.7. It is transparent to translucent with refractive indices of 1.46 to 1.51.[5] The mineral will effloresce at room temperature, producing nesquehonite.[6]

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. ^ "Lansfordite Mineral Data". www.webmineral.com. Retrieved 2021-02-15.
  3. ^ Liu, B.N.; Zhou, X.T.; Cui, X.S.; Tang, J.G. (1990). "Synthesis of lansfordite MgCO3*5H2O and its crystal structure investigation". Science in China. B33: 1350–1356.
  4. ^ "LANSFORDITE". euromin.w3sites.net. Retrieved 2021-02-15.
  5. ^ "Lansfordite". www.mindat.org. Retrieved 2021-02-15.
  6. ^ "Lansfordite" (PDF). Handbook of Mineralogy. Retrieved 15 February 2021.


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