Forms
The most common magnesium carbonate forms are the anhydrous salt called magnesite (MgCO3) and the di, tri, and pentahydrates known as barringtonite (MgCO3·2H2O), nesquehonite (MgCO3·3H2O), and lansfordite (MgCO3·5H2O), respectively. Some basic forms such as artinite (MgCO3·Mg(OH)2·3H2O), hydromagnesite (4MgCO3·Mg(OH)2·4H2O), and dypingite (4MgCO3· Mg(OH)2·5H2O) also occur as minerals.
Magnesite consists of white trigonal crystals. The anhydrous salt is practically insoluble in water, acetone, and ammonia. All forms of magnesium carbonate react in acids. Magnesium carbonate crystallizes in the calcite structure where in Mg2+ is surrounded by six oxygen atoms. The dihydrate one has a triclinic structure, while the trihydrate has a monoclinic structure.
References to 'light' and 'heavy' magnesium carbonates actually refer to the magnesium hydroxy carbonates hydromagnesite and dypingite (respectively).
Read more about this topic: Magnesium Carbonate
Famous quotes containing the word forms:
“Psychoanalysis can unravel some of the forms of madness; it remains a stranger to the sovereign enterprise of unreason. It can neither limit nor transcribe, nor most certainly explain, what is essential in this enterprise.”
—Michel Foucault (1926–1984)
“The idea which man forms of beauty imprints itself throughout his attire, rumples or stiffens his garments, rounds off or aligns his gestures, and, finally, even subtly penetrates the features of his face.”
—Charles Baudelaire (1821–1867)
“The government, which is the supreme authority in states, must be in the hands of one, or of a few, or of the many. The true forms of government, therefore, are those in which the one, the few, or the many, govern with a view to the common interest.”
—Aristotle (384–323 B.C.)