Assertion: calcium oxide's magnesium oxide | /r/HasProperty | needed
Facets:
Source sentences:
text: In industrial glass: Chemical compounds Lime is obtained from limestone (calcium carbonate) or from dolomite (calcium magnesium carbonate) when magnesium oxide is also needed.
text: (calcium carbonate) or from dolomite (calcium magnesium carbonate) when magnesium oxide is also needed.