Chemistry:Lansfordite
From HandWiki
| Lansfordite | |
|---|---|
 Lansfordite crystals in Switzerland | |
| General | |
| Category | Carbonates |
| Formula (repeating unit) | MgCO3·5H2O |
| 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 |
| |re|er}} | Vitreous (if fresh) |
| Streak | White |
| Diaphaneity | Translucent, opaque after exposure |
| Specific gravity | 1.6 |
| Density | 1.6 |
| Birefringence | 0.042 |
Lansfordite is a mineral of magnesium carbonate (MgCO3). It represents the pentahydrate of magnesium carbonate, and has the total formula 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. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ "Lansfordite Mineral Data". http://www.webmineral.com/data/Lansfordite.shtml.
- ↑ 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". http://euromin.w3sites.net//mineraux/LANSFORDITE.html.
- ↑ "Lansfordite". https://www.mindat.org/min-2324.html.
- ↑ "Lansfordite". http://www.handbookofmineralogy.com/pdfs/lansfordite.pdf.
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