Lansfordite
(repeating unit)MgCO3·5H2O IMA symbol Lfd[1] Strunz classification 5/D.01-30 Dana classification 15.1.6.1 Crystal system Monoclinic Space group P21/c (No. 14) Unit cell a=7.3458 Å, b=7.6232 Å, c=12.4737 Å, β=101.722° Identification Formula mass 174.39 Colour Colourless, white after exposure Crystal habit Crystals, stalactites terminated by crystal faces, efflorescences, parallel growths. Cleavage Perfect, Distinct Mohs scale hardness 2.5 Luster Vitreous (if fresh) Streak White Diaphaneity Translucent, opaque after exposure Specific gravity 1.6 Density 1.6 Birefringence 0.042
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
- ^ 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.
- ^ "Lansfordite Mineral Data". www.webmineral.com. Retrieved 2021-02-15.
- ^ 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.
- ^ "LANSFORDITE". euromin.w3sites.net. Retrieved 2021-02-15.
- ^ "Lansfordite". www.mindat.org. Retrieved 2021-02-15.
- ^ "Lansfordite" (PDF). Handbook of Mineralogy. Retrieved 15 February 2021.
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