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:
“I may not tell
of the forms that pass and pass,
of that constant old, old face
that leaps from each wave
to wait underneath the boat
in the hope that at last she’s lost.”
—Hilda Doolittle (1886–1961)
“All ... forms of consensus about “great” books and “perennial” problems, once stabilized, tend to deteriorate eventually into something philistine. The real life of the mind is always at the frontiers of “what is already known.” Those great books don’t only need custodians and transmitters. To stay alive, they also need adversaries. The most interesting ideas are heresies.”
—Susan Sontag (b. 1933)
“Culture’s essential service to a religion is to destroy intellectual idolatry, the recurrent tendency in religion to replace the object of its worship with its present understanding and forms of approach to that object.”
—Northrop Frye (b. 1912)