[JWP]

What is the chemical difference between light and heavy magnesium carbonate?

[Mitch]

light and heavy being defined as what?

[mike]

I didn't think there was a chemical difference. I thought one was just denser (ie a finer grade and therefore more tightly packed) than the other

I could be wrong....

[Morphic flip]

it`s the same with sodium carbonate, bulk density`s are different.
light - normally higher purity as well.
normal grade is more granular.

[asmaaalseedaraa]

What is the chemical difference between light and heavy magnesium carbonate?

the difference is just restracted in chemical structure which the light magnesium carbonate has 3 of H2O in it and 4 of H2O for  a heavy.

[UnintentionalChaos]

I think that this refers to the method of preparation and resulting composition. A soluble magnesium salt added to a cold carbonate solution affords a voluminous product of basic magnesium carbonate (a poorly defined mixture of magnesium carbonate and magnesium hydroxide). A hot or boiling carbonate solution, or preferably a bicarbonate solution, yields much more pure magnesium carbonate as a precipitate which settles rapidly from the solution, hence "heavy." I remember this discussion from somewhere...I wouldn't quote me on this though...