MGX's grade is = 43%
When they test the grades,
It involves heating the magnesite with flame which reduces
MgCO3 to -------> MgO
They weight it before
Then weight it after
What is lost ( LOI ) loss of ignition due to flame
Removing ( C + 2 O's )
The latter volume is weighed
= grade of magnesium
= 43%
If they were to weigh MGCO3 without performing - LOI
Resources would be greater by weight of, C + 2 extra O's
MgO ( can be in the form of just oxide powder.
Yet.... melting MgO ( technically ) converts to Mg metal
BUT.... O ( oxygen ) is still apart of the metal.
How much... ?
Depends on which research paper one reads
Rust is a great example
when melted ( rust )
the oxygen bonds break away and iron oxide reduction turns to
pure iron metal.
if oxygen bonds release from the iron oxide then...
how many oxygen molecules might remain ?
In theory.... none.
Otherwise the iron would have oxidation.
It's how i see it.
But... do your own research to verify.