Meerschaum is a mineral with a hardness of 3 out of 10 on the Mohs scale of mineral hardness [?]. These Monoclinicly structured gems are made of hydrated magnesium silicate, their full chemical compound being Mg4Si6O15(OH)2.6H2O.
Meerschaum is a clay-like hydrous magnesium silicate. It has no crystals, and occurs as earthy aggregates, porcellanous masses, nodular, and porous. In the fresh state it is soapy and soft, but hard when dried. It sticks to the tongue and its taste sets the teeth on edge.
It is opaque, has flat conchoidal, earthy fracture, and an orthorhombic microcrystalline system.
Because of its high porosity, meerschaum can float on water. It is very porous and has a dull, greasy luster. The color may be white, reddish, yellowish, greyish or bluish green.
It is soft, light, and can easily be cut with a blade. It is so fine-grained that even very thin fragments are opaque. It becomes plastic when mixed with water. It is almost infusible and insoluble in acids.
It is formed as the decomposition product of serpentine, and occurs as concretions within that rock.
The only imporant occurrence is in Eskischehir, Anatolia (Turkey). Nodular masses also occur in Spain, Greece, Czechoslovakia, Morocco, and the USA (Utah, California, Pennsylvania, and New Mexico).
Meerschaum is also called Sepiolite.
Other names include agaric chalk, keffekilite, Bosnian sepiolite, falcondoite (when it contains nickel), loughlinite (when sodium is present), and piedra de savon Maroc (from Morocco, used as soapdish).
Meerschaum takes its name from the German, meaning "sea foam."
Meerschaum is used for heat and sound insulation, and is worked into bowls for tobacco pipes and cigarette holders, which, because of the smoke, gradually becomes yellowish. It is also made into costume jewelry. It becomes lustrous when impregnated with grease.