Lansfordite
Template:Short description Template:Infobox mineral Lansfordite is a mineral of magnesium carbonate (Template:Chem). It represents the pentahydrate of magnesium carbonate, and has the total formula Template:Format molecular formula.<ref name=webmineral>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Landsfordite was discovered in 1888 in a coal mine in Lansford, Pennsylvania. It crystallizes in the monoclinic system (space group P21/c<ref>Template:Cite journal</ref>) and typically occurs as colorless to white prismatic crystals and stalactitic masses.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The mineral will effloresce at room temperature, producing nesquehonite.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>