Lansfordite
Encyclopedia
Lansfordite is a hydrated magnesium
carbonate mineral
with composition: MgCO3·5H2O. Landsfordite was discovered in 1888 in a coal
mine in Lansford, Pennsylvania
. It crystallizes in the monoclinic system and typically occurs as colorless to white prismatic crystals and stalactitic masses. 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 1.52.
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
carbonate mineral
Carbonate minerals
Carbonate minerals are those minerals containing the carbonate ion: CO32-.-Anhydrous carbonates:*Calcite group: Trigonal**Calcite CaCO3**Gaspeite CO3**Magnesite MgCO3**Otavite CdCO3**Rhodochrosite MnCO3**Siderite FeCO3**Smithsonite ZnCO3...
with composition: MgCO3·5H2O. Landsfordite was discovered in 1888 in a coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
mine in Lansford, Pennsylvania
Lansford, Pennsylvania
Lansford is a borough in Carbon County, Pennsylvania, located northwest of Allentown and 9 miles south of Hazleton. Settled in 1845, Lansford was incorporated in 1876. In 1900, 4,888 people lived in Lansford; in 1910, 8,321 people inhabited it, and in 1940, 8,710 residents called Lansford home....
. It crystallizes in the monoclinic system and typically occurs as colorless to white prismatic crystals and stalactitic masses. It is a soft mineral, Mohs hardness of 2.5, with a low specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...
of 1.7. It is transparent to translucent with refractive indices
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
of 1.46 to 1.52.